Platelet sufficiency. Platelet Count (PLT) Blood Test: Understanding Your Blood’s Clotting Ability
What is a platelet count test. How does it measure your blood’s clotting ability. When should you get a platelet count test. What are the symptoms of abnormal platelet levels. How can you get a platelet count test.
What Is a Platelet Count (PLT) Blood Test?
A platelet count test is a crucial laboratory examination that measures the number of platelets in your blood. Platelets, also known as thrombocytes, are tiny, round cell fragments that play a vital role in blood clotting. These microscopic components work alongside red and white blood cells to maintain your body’s hemostasis.
Why are platelets so important? They are the body’s first line of defense against bleeding. When you experience an injury, platelets rush to the site and form a plug, effectively stopping the bleeding. This process is essential for wound healing and preventing excessive blood loss.
The Science Behind Platelet Counting
How does the test actually count these minuscule blood components? Most modern laboratories use automated hematology analyzers. These sophisticated machines can rapidly process blood samples and provide accurate platelet counts. In some cases, especially when results are abnormal or inconclusive, a manual count using a peripheral blood smear may be necessary.
The results of a platelet count test are typically reported as the number of platelets per microliter of blood. This standardized measurement allows healthcare professionals to quickly assess whether your platelet levels fall within the normal range or if there are any concerning deviations.
Why Is a Platelet Count Test Performed?
Healthcare providers may order a platelet count test for various reasons. It’s often included as part of routine blood work, such as a complete blood count (CBC). However, there are specific situations where this test becomes particularly important:
- Diagnosing platelet disorders
- Assessing bleeding risk before surgery
- Monitoring the effects of certain medications, like blood thinners
- Evaluating the progress of chemotherapy treatments
- Investigating unexplained bruising or bleeding
Is a platelet count test always necessary? Not always, but it’s a valuable tool for healthcare providers to assess your overall health and identify potential blood disorders. If you’re experiencing symptoms that might be related to abnormal platelet levels, your doctor may recommend this test as part of a comprehensive evaluation.
Understanding Normal Platelet Levels
What constitutes a normal platelet count? For most adults, a normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. However, it’s important to note that these ranges can vary slightly depending on the laboratory and the specific population being tested.
Are there factors that can affect platelet counts? Indeed, several factors can influence your platelet levels:
- Age: Platelet counts tend to decrease slightly as we get older
- Gender: Women may have slightly higher platelet counts than men
- Pregnancy: Platelet counts can decrease during pregnancy
- Altitude: Living at high altitudes can affect platelet production
- Certain medications: Some drugs can impact platelet levels
Understanding these factors helps healthcare providers interpret your test results more accurately and determine if any further investigation or treatment is necessary.
Symptoms of Low Platelet Count (Thrombocytopenia)
When platelet levels drop below normal, a condition known as thrombocytopenia can occur. This condition can range from mild to severe, with symptoms varying accordingly. What signs should you look out for if you suspect low platelet levels?
- Easy bruising: Even minor bumps may result in noticeable bruises
- Petechiae: Small, reddish-purple spots on the skin
- Prolonged bleeding from cuts or wounds
- Frequent nosebleeds or bleeding gums
- Heavy menstrual flow in women
- Blood in urine or stool
- Fatigue and weakness
Why do these symptoms occur? With fewer platelets available, your blood’s ability to form clots is compromised. This makes it easier for small blood vessels to leak, resulting in bruising and bleeding. In severe cases, internal bleeding can be a serious concern.
Causes of Low Platelet Count
What can lead to a decrease in platelet levels? There are numerous potential causes:
- Autoimmune disorders (e.g., lupus, immune thrombocytopenia)
- Viral infections (e.g., HIV, hepatitis C)
- Certain medications
- Bone marrow disorders
- Alcohol abuse
- Vitamin B12 or folate deficiency
- Pregnancy complications (e.g., HELLP syndrome)
Identifying the underlying cause is crucial for effective treatment. Your healthcare provider may order additional tests to pinpoint the exact reason for your low platelet count.
Symptoms of High Platelet Count (Thrombocytosis)
On the other end of the spectrum, an elevated platelet count, known as thrombocytosis, can also pose health risks. What symptoms might indicate high platelet levels?
- Headaches
- Dizziness or lightheadedness
- Chest pain
- Weakness or numbness on one side of the body
- Visual changes
- Unexplained weight loss
- Burning or tingling sensations in hands and feet
Why are these symptoms concerning? High platelet counts increase the risk of blood clots forming in your blood vessels. These clots can potentially travel to vital organs like the heart, lungs, or brain, leading to serious complications such as heart attacks or strokes.
Causes of High Platelet Count
What factors can contribute to an elevated platelet count? Several conditions and circumstances may lead to thrombocytosis:
- Inflammatory disorders (e.g., rheumatoid arthritis, inflammatory bowel disease)
- Infections
- Iron deficiency anemia
- Certain types of cancer
- Splenectomy (surgical removal of the spleen)
- Myeloproliferative disorders
- Medications (e.g., epinephrine, vincristine)
As with low platelet counts, determining the root cause of thrombocytosis is essential for proper management and treatment. Your healthcare provider may recommend additional tests or consultations with specialists to develop an appropriate treatment plan.
How to Prepare for a Platelet Count Test
Preparing for a platelet count test is generally straightforward. In most cases, no special preparations are required. However, there are a few things to keep in mind:
- Inform your healthcare provider about all medications you’re taking, including over-the-counter drugs and supplements
- If you’re on blood thinners, your doctor may provide specific instructions
- Fasting is typically not required for a platelet count test
- Wear comfortable clothing with sleeves that can be easily rolled up
- If you have a history of difficult blood draws, mention this to the phlebotomist
Are there any risks associated with the test? The platelet count test is a routine blood test with minimal risks. You may experience slight discomfort or bruising at the needle insertion site, but serious complications are rare.
The Blood Drawing Process
What can you expect during the blood draw? The process is usually quick and straightforward:
- A healthcare professional will clean the area, usually the inside of your elbow or back of your hand
- A tourniquet may be applied to make your veins more visible
- A needle is inserted into your vein to collect the blood sample
- The blood is collected in one or more vials
- The needle is removed, and pressure is applied to stop any bleeding
- A bandage is placed over the puncture site
The entire process typically takes just a few minutes. After the blood draw, you can usually resume your normal activities immediately, unless otherwise instructed by your healthcare provider.
Interpreting Platelet Count Test Results
Once your blood sample has been analyzed, your healthcare provider will interpret the results. How are platelet count test results typically reported?
- Normal range: 150,000 to 450,000 platelets per microliter
- Low platelet count (thrombocytopenia): Below 150,000 platelets per microliter
- High platelet count (thrombocytosis): Above 450,000 platelets per microliter
It’s important to note that these ranges can vary slightly between laboratories and populations. Your healthcare provider will consider your specific circumstances when interpreting your results.
What Do Abnormal Results Mean?
If your platelet count falls outside the normal range, what does this indicate? Abnormal results don’t always mean you have a serious condition. Various factors can temporarily affect platelet levels, including:
- Recent infections
- Certain medications
- Strenuous exercise
- Pregnancy
- Altitude changes
Your healthcare provider will consider these factors along with your medical history and any symptoms you’re experiencing. In some cases, they may recommend repeat testing or additional diagnostic procedures to determine the underlying cause of abnormal platelet levels.
Treatment Options for Platelet Disorders
If a platelet disorder is diagnosed, what treatment options are available? The appropriate treatment will depend on the specific condition and its severity. Some common approaches include:
For Low Platelet Count (Thrombocytopenia)
- Corticosteroids to suppress the immune system
- Immunoglobulins to boost platelet production
- Thrombopoietin receptor agonists to stimulate platelet production
- Platelet transfusions for severe cases
- Treating underlying conditions (e.g., addressing vitamin deficiencies)
For High Platelet Count (Thrombocytosis)
- Low-dose aspirin to reduce clot formation
- Hydroxyurea to lower platelet production
- Anagrelide to decrease platelet count
- Plateletpheresis for urgent reduction of platelet levels
- Treating underlying conditions (e.g., managing inflammatory disorders)
The goal of treatment is to bring platelet levels back to a normal range and prevent complications. Your healthcare provider will work with you to develop a personalized treatment plan based on your specific needs and circumstances.
Lifestyle Considerations for Platelet Health
While medical treatments are often necessary for platelet disorders, are there lifestyle changes that can support platelet health? Indeed, several lifestyle factors can influence platelet function and overall blood health:
- Maintain a balanced diet rich in vitamins and minerals
- Stay hydrated to support blood volume and flow
- Exercise regularly to promote cardiovascular health
- Manage stress through relaxation techniques or mindfulness practices
- Avoid smoking and limit alcohol consumption
- Be cautious with over-the-counter medications that may affect platelet function
These lifestyle considerations can complement medical treatments and contribute to overall well-being. However, it’s important to consult with your healthcare provider before making significant changes to your diet or exercise routine, especially if you have a diagnosed platelet disorder.
Monitoring Platelet Levels Over Time
For individuals with platelet disorders or those at risk, how often should platelet levels be monitored? The frequency of testing will depend on your specific condition and treatment plan. Your healthcare provider may recommend:
- Regular follow-up appointments to assess symptoms and overall health
- Periodic blood tests to track platelet counts
- Adjustments to medication dosages based on test results
- Additional testing if new symptoms develop or existing symptoms worsen
Consistent monitoring allows healthcare providers to track the effectiveness of treatments and make necessary adjustments. It’s crucial to attend all scheduled appointments and communicate any changes in your health to your medical team.
Advances in Platelet Research and Future Treatments
What does the future hold for platelet disorder treatments? Ongoing research in hematology and immunology is paving the way for innovative approaches to managing platelet disorders. Some exciting areas of study include:
- Gene therapy for inherited platelet disorders
- Development of artificial platelets for transfusion
- Targeted immunotherapies for autoimmune thrombocytopenia
- Improved platelet storage techniques for transfusions
- Novel drugs that specifically modulate platelet production and function
These advancements hold promise for more effective and personalized treatments in the future. As research progresses, individuals with platelet disorders may have access to a wider range of therapeutic options.
Participating in Clinical Trials
For those interested in contributing to platelet research, how can one get involved in clinical trials? Clinical trials offer opportunities to access cutting-edge treatments and contribute to medical knowledge. If you’re considering participation:
- Discuss the possibility with your healthcare provider
- Research ongoing trials through reputable databases like ClinicalTrials.gov
- Carefully review eligibility criteria and potential risks and benefits
- Ask questions about the trial protocol and what participation entails
- Consider seeking a second opinion before enrolling
Participation in clinical trials is voluntary and should be carefully considered. Your healthcare provider can help you weigh the potential benefits and risks based on your individual health situation.
Platelet Count (PLT) Blood Test
Test Quick Guide
The platelet count test is a lab test that measures the number of platelets you have in your blood. Platelets, also known as thrombocytes, are tiny, round cell fragments that circulate in your blood. They are essential for the formation of blood clots, masses of blood the body forms to stop bleeding.
Platelets are one of three main components of the blood along with red and white blood cells.
Platelet count testing can detect when platelet levels are too low or too high. Low platelet levels make it difficult for the body to form blood clots, which can cause excessive bleeding. High platelet levels can cause too much clotting. Blood clots in the blood vessels can become lodged in the lungs, intestines, brain, or heart, and this can result in serious medical conditions.
About the Test
Purpose of the test
The purpose of a platelet count test is to assess your blood’s ability or inability to clot. While platelet counts are often included on multi-test panels such as the complete blood count, this test can also be done on its own.
The platelet count may be conducted by your doctor as part of routine blood testing. Platelet counts are also ordered to:
- Diagnose a platelet disorder
- Assess the risk of bleeding before surgery
- Monitor you during medical treatments such as blood thinners or chemotherapy
The platelet count is used to diagnose disease and help determine the cause of excess bleeding or clotting. Both high and low platelet counts can have associated risks that can range from not causing any noticeable health problems to being very serious and life-threatening.
A platelet count test is also used to monitor if you have been diagnosed with a clotting condition. Regularly conducting a platelet count allows doctors to check the effectiveness of medications that increase or decrease the blood’s ability to form a clot.
What does the test measure?
A platelet count measures the platelets in your sample of blood with the results reported as a number of platelets per microliter. Measuring a platelet count typically involves analyzing a blood sample using automated laboratory technology. In some cases, automated results need to be confirmed using a peripheral blood smear, a method of manually measuring the number of platelets in a blood sample.
When should I get a platelet count test?
Your doctor may recommend you take a platelet count test during a check-up as part of a broader screening panel such as a complete blood count. They might also recommend platelet count testing if you have symptoms associated with abnormal platelet levels. Low or high platelet counts may or may not cause signs and symptoms. It’s important to speak with your doctor any time you notice health changes that concern you.
Symptoms of low platelet levels
Bleeding is the main sign and symptom of a low platelet count. Early signs of a low platelet count can occur in any part of the body and may include (but are not limited to):
- Purple, reddish, or brown bruising, occurring easily and often
- Small red and purple dots on the skin
- Abnormally prolonged bleeding, including from minor cuts
- Bleeding from the nose or mouth
- Atypically heavy vaginal bleeding, especially during menstruation
- Excessive bleeding during dental work, including flossing or surgery
- Blood in the urine or stool, or bleeding from the rectum
Symptoms of high platelet levels
Signs of high platelet levels are primarily related to blot clots and bleeding. They may include:
- Weakness or dizziness
- Unexpected headache
- Chest pain
- Tingling of the hands and feet
- Pain, swelling, warmth, and/or tenderness in one or both of the lower extremities
In some instances, extremely high platelet counts may result in signs and symptoms that mirror low platelet counts. Signs and symptoms of high platelet levels include:
- Bleeding from many sites of the body at once
- Shortness of breath
- Confusion and changes in memory or behavior
- Fever
Monitoring platelet levels
Your health care provider may also order a platelet count test when monitoring other health conditions. If you have been diagnosed with a disease that puts you at risk for high or low platelets, or if you have had abnormal results on past platelet count tests, your doctor may test you for platelet levels periodically. This allows your doctor to monitor your overall health and assess the effectiveness of treatment.
Finding a Platelet Count Test
How can I get a platelet count test?
Typically, a platelet count test is done by a licensed professional in a health care setting using a blood sample. The test can be conducted on its own or as part of a complete blood count test that is done in a doctor’s office, clinic, laboratory, or hospital.
A platelet count test is normally prescribed by a doctor. Talk with your health care provider if you have symptoms that could be related to abnormal platelet levels or if you are interested in a platelet count test.
You can order a platelet test online with a blood draw at a local lab.
Can I take the test at home?
Currently, there are no at-home testing options available for the platelet count. A medical professional conducts platelet counts and they are analyzed by a laboratory from a blood draw sample in a health care setting.
How much does the test cost?
The cost of a platelet count test depends on whether or not you have insurance and if that insurance plan covers the test. Some other factors that affect the price are the setting of the blood draw and the lab to which the sample is sent.
For details on the expected cost for a platelet count that you may be responsible for, check with your doctor or insurance provider about any associated copays or deductibles.
Taking a Platelet Count Test
The platelet count test requires a blood sample ordered by a doctor that is collected in a medical setting by a licensed professional, such as a phlebotomist.
Before the test
No special preparation is required prior to a platelet count test unless specified by your health care provider. They may order the platelet count by itself, as part of the complete blood count, or along with other blood tests.
If you are receiving more than one blood test, your provider may ask you to not eat anything for a certain amount of time prior to your test. Contact your health care provider for detailed instructions if you have questions or concerns about any test preparation.
During the test
A blood sample for a platelet count is taken from a vein in your arm or forearm by a phlebotomist, a health care professional trained in drawing blood. They tie a tourniquet around the upper part of your arm to increase the blood pressure in the vein so it is easier to find.
They will cleanse your skin around the vein with an antiseptic wipe and insert a needle to draw blood from the vein. Next, they attach a vacuum tube to the needle to help pull blood from the vein and, if drawing blood for multiple tests, they may attach several different tubes.
There may be a brief stinging sensation when the needle is initially inserted into your arm. This pain usually does not last long, and the test itself can be completed in under one minute.
After the test
After the procedure is complete, the phlebotomist will apply folded gauze and an adhesive bandage over the site to reduce bleeding, as well as remove the tourniquet and needle.
The main risk associated with blood draws is local bruising at the site of the needle puncture. This bruising may last longer than usual if you are experiencing low platelets. Because low platelet counts reduce the clotting potential of your blood it may be suggested to keep the bandage on for a specified period of time.
The phlebotomist may ask you to stay at the facility for a few minutes so they can monitor you for dizziness before you return to normal activities including walking and driving.
Platelet Count Test Results
Receiving test results
The results from a platelet count can be available in a few minutes or up to a few days after the blood sample arrives at the laboratory, depending on the equipment that is used.
If not available immediately, a copy of your results may be sent to you by mail or through an electronic health portal. It is also possible that your health care provider may call you to discuss the results, retest, or schedule an appointment to review them together.
Interpreting test results
Results are interpreted in comparison with the test reference range, the results range that is considered to be normal. Platelet test results that fall outside of the reference range indicate that platelet levels may be too low or too high.
The reference range for platelet counts gives a wide range of normal results. This reflects the range in platelet levels that allows most people to function without adverse health issues. Specific reference ranges vary from one laboratory to the next, and your results are considered in the context of your overall health risk factors.
The American Board of Internal Medicine lists a typical platelet count reference range as 150,000 to 450,000 per microliter.
Platelet counts tend to be slightly higher in certain populations, including:
- Females
- Younger people when compared with older people
- Non-Hispanic Black individuals when compared with white individuals
Your doctor may consider retesting if you have significant decreases or increases in your platelet numbers from one test to the next even if they are within the normal range as this may indicate a potential problem.
If you have a platelet count test result that is lower than expected, your doctor will consider whether another condition may be causing or contributing to a decrease in platelets. Some causes and risk factors associated with low platelet counts are:
- Certain cancers
- Aplastic anemia
- Autoimmune diseases and conditions
- Certain medications
- Viral or bacterial infections
- Genetic condition
- Heavy alcohol use
- Pregnancy
Other conditions can cause or increase the risk for high platelet counts:
- Rare genetic conditions
- Bone marrow conditions
- Certain cancers
- Iron deficiency or hemolytic anemia
- Inflammatory disease
- Infections such as tuberculosis
- Adverse medication reactions
- Severe blood loss
- Recovery from low blood platelet counts caused by heavy alcohol use or vitamin B12 or folate deficiency
- Physical activity
Depending on the results of your platelet count test, it is possible that your doctor will order follow-up tests to learn more about your overall health. Commonly ordered follow-up tests include:
- Complete blood count: If your platelet count does not match the context of your symptoms and other test results, your doctor may reorder a complete blood count panel to confirm the results prior to more extensive evaluations or interventions.
- Peripheral blood smear: Automated instrumentation is most often used to measure blood counts, including platelet counts. A peripheral blood smear involves manually analyzing the blood sample under a microscope and can be used to confirm an abnormal result on an automated platelet count.
- HIV or HCV test: Low platelet counts are often seen if you have human immunodeficiency virus (HIV) or hepatitis C virus (HCV) infection. Follow-up testing may be used to rule out or confirm the existence of HIV or HCV as the cause of low platelets.
Other tests may be conducted to diagnose the cause of abnormal platelets. Testing depends on the specific conditions that are suspected. If you receive an abnormal platelet count result, your doctor can help you understand what follow-up testing is recommended for you and why.
It may be helpful to ask your doctor the following questions about your platelet count results:
- Was my test result abnormal? If so, was it abnormally high or low?
- What does my platelet count indicate about my health?
- Are there any diagnoses to be made based on my platelet count results?
- Will any follow-up tests be needed?
- Will I be prescribed medication based on my results?
- Platelet Function Tests
Learn More - PTT Blood Test (Partial Thromboplastin Time)
Learn More - PT/INR Test (Prothrombin Time and International Normalized Ratio)
Learn More - Protein C and Protein S
Learn More - CBC Blood Test (Complete Blood Count)
Learn More - HIV Testing
Learn More - Hepatitis C Test
Learn More - Blood Smear
Learn More - von Willebrand Factor
Learn More - D-Dimer Test
Learn More
Resources
- National Library of Medicine: Platelet Disorders
- National Library of Medicine: Bleeding Disorders
Sources
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What are high, low, and normal values
A platelet count measures the average platelet level in a person’s blood. High or low platelet levels can increase the risk of clotting or excessive bleeding.
Platelets, also called thrombocytes, are fragments of larger cells made in the bone marrow called megakaryocytes. These fragments are crucial to wound healing.
The mean platelet count blood test is typically part of a complete blood count (CBC) test. A CBC reveals important information about the number of different blood cells in the body.
A person’s platelet levels can change with age, and certain medical conditions can also affect them.
A platelet count that is too low or too high can lead to health complications. A low platelet count is known as thrombocytopenia, while a high platelet count is known as thrombocytosis.
Tests measure average platelet levels per microliter (mcL) of blood. Below are guideline platelet levels.
Result | Platelet count |
---|---|
high platelet level (thrombocytosis) | more than 450,000 |
normal platelet level | 150,000–450,000 |
low platelet level (thrombocytopenia) | less than 150,000 |
However, some studies suggest that normal platelet levels should take into account other variables, such as a person’s age and sex.
A high platelet count can occur when something causes the bone marrow to make too many platelets. When the reason is unknown, it is called primary or essential thrombocytosis.
When excess platelets are due to an infection or other condition, it is called secondary thrombocytosis.
Higher risk of blood clots
A person’s blood clots more quickly when they have too many platelets.
Clotting is a natural protection against bleeding. The body produces more platelets during and following an injury.
However, because platelets cause blood clotting, they can also cause dangerous blood clots in the arms or legs. The blood clot may break off or travel to another area of the body.
The risk of a blood clot is higher in people confined to bed by illness or who cannot move their limbs.
Someone who has a high platelet count because of a recent injury but who must remain in bed may need monitoring to reduce the risk of blood clots as a result.
A low platelet count can make it difficult for the blood to clot, putting a person at risk of excessive bleeding. The cause may be an inherited tendency not to produce enough platelets, but the cause may also be unknown. Or it may be due to an underlying medical condition.
Higher risk of spontaneous bleeding
If the blood platelet count falls below 20,000 per mcL, a person can begin bleeding spontaneously. This is a medical emergency, and people who experience spontaneous bleeding may require a blood, or platelet, transfusion.
Low platelet count increases the risk of death in people who experience a traumatic injury.
Several factors can cause a person’s platelet levels to change. These include acute and chronic medical conditions and age.
Causes of high platelet counts
Some temporary conditions can cause a higher than normal platelet count. A doctor may order a retest a few days or weeks later if this happens. Some common reasons for high platelet levels include:
- recovering from a recent injury
- recovering from blood loss after surgery
- recovering from excessive drinking or vitamin B12 deficiency
- intense physical activity or exertion, such as from running a marathon
- using birth control pills
If a person’s platelet count remains high, chronic medical conditions may be responsible. These may include:
- Cancer: Lung, stomach, breast, and ovarian cancers, as well as lymphoma, can cause high platelet counts. Additional blood testing, imaging scans, or a biopsy can test for cancer.
- Anemia: People with iron deficiency or hemolytic anemia may have high platelets. Further blood testing can detect most forms of anemia.
- Inflammatory disorders: Diseases that cause an inflammatory immune response, such as rheumatoid arthritis or inflammatory bowel disease (IBD), can increase platelet count. A person will have other symptoms in most cases.
- Infections: Some infections, such as tuberculosis, can cause high platelets.
- Splenectomy: Removal of the spleen can cause a temporary increase in platelets.
Causes of low platelet counts
Common causes of low platelet volume include:
- Viruses: Viruses such as mononucleosis, HIV, AIDS, measles, and hepatitis may deplete platelets.
- Medication: Drugs, such as aspirin, h3-blockers, quinidine, antibiotics containing sulfa, and some diuretics may lower platelet count.
- Cancer: Cancer that has spread to the bone marrow can harm the body’s ability to make new platelets. Lymphoma and leukemia are common culprits.
- Anemia: A type of anemia called aplastic anemia reduces the number of all kinds of blood cells, including platelets.
- Infection: A bacterial infection, especially the blood infection called sepsis, can reduce platelet count.
- Autoimmune disorders: Autoimmune diseases such as lupus and Crohn’s disease lower platelet count by causing the body to attack its tissue.
- Chemotherapy: Chemotherapy harms existing tissue and cancer cells, making it difficult for the body to produce platelets.
- Poisoning: Exposure to some pesticides can damage platelets.
- Cirrhosis: Liver cirrhosis, often due to excessive drinking, can reduce platelet count.
- Chronic bleeding: Any disorder that causes ongoing uncontrolled bleeding, such as stomach ulcers, can deplete platelets.
Platelet count tends to decline with age. A platelet count that is lower than it once was or on the lower end of normal may not be a cause for concern in an older adult — especially if there are no other symptoms.
A platelet count test reveals the average number of platelets a person has per microliter of blood.
Doctors can perform the test on its own or as part of a CBC test. They will often perform a platelet count test if they suspect a disorder that affects platelet count.
The test involves drawing blood from a vein in the arm or hand.
Obtaining a sample of blood from a vein takes a few minutes and generally causes only minimal discomfort. Occasionally, some people may feel queasy or light-headed while the blood is drawn or shortly after. Taking slow deep breaths is usually enough to calm these feelings. Some people may develop a small mark or bruise.
A technician will put the blood sample into a machine that counts the number of platelets and produces a report of the findings.
Is it safe?
The test is safe, and complications are rare. People with bleeding disorders should tell their doctor about any history of bleeding issues. Most people find that the test is only a brief inconvenience and a source of mild discomfort.
When do you get the results?
The amount of time it takes to get the results varies.
Hospitals administering the test for emergencies or people about to undergo surgery often get the results almost immediately. It can take a few days to get the results when a doctor’s office orders the test from an outside lab.
Changes in platelet count may mean that a person has a chronic illness or an issue with the bone marrow.
It is generally not possible, however, to diagnose a medical condition based on platelet count alone. People should talk with a doctor about further testing if a blood test reveals low platelets.
It is advisable to inform the doctor about any other symptoms, which can help narrow down testing options.
Read this article in Spanish.
If an operation is to be done… — Unimed in Moscow
From the archive of the Novosti A/O Unimed newspaper
Gulidova O.V.
Experienced surgeons know that even when using well-established technologies and tactics for managing an operating patient, the doctor is not immune from emergencies. Of particular danger are surgical and postoperative hemostasiological complications, which manifest themselves in the form of bleeding or thrombosis.
The risk of postoperative thromboembolism increases with increasing age of patients, types, severity and duration of surgical interventions, the background state of the hemostasis system (the presence of hereditary or acquired thrombophilic conditions, vascular diseases and hemorheological disorders), the presence of diseases that create a particularly high predisposition to thrombosis – varicose veins veins, hyperlipidemia and atherosclerosis, diabetic angiopathy, malignant neoplasms (oncothrombosis), etc.
A special group of risk factors are hereditary and acquired (secondary) thrombophilias, among which forms characterized by polyglobulia (high hematocrit and hemoglobin levels in the blood), hyperthrombocytosis (more than 450-500´10 9 /l), hyperaggregation of platelets, anomalies of coagulation factors, especially factors V and II, making them resistant to physiological anticoagulants, deficiency of the latter (antithrombin III, proteins C and S) and components of the fibrinolysis system, antiphospholipid syndrome.
Increase the risk of thrombosis and some medications – taking many hormonal contraceptives and a number of anticancer drugs, in some patients – heparin therapy (the so-called “heparin thrombotic thrombocytopenia”, GTT), etc.
Accounting for all of the listed risk factors separately and together allows for timely targeted prevention of thromboembolism. The groups of people with a very high risk of such thromboembolism, regardless of all other factors, include patients undergoing orthopedic operations on the lower extremities, including arthroplasty, operated on for visceral cancers, patients with any type of thrombophilia and with a history of lower extremity vein thrombosis.
The risk of arterial thromboembolism is especially high in patients with atherosclerosis who have had NCC and strokes in the past, with high blood pressure, paroxysmal or persistent atrial fibrillation, after commissurotomy and implantation of artificial heart valves, as well as with aneurysms of the main arteries. This risk is exacerbated by certain thrombophilias, hyperhomocysteinemia, diabetes, obliterating diseases of the arteries of the lower extremities. With a number of these types of pathology, there is a high risk of developing both arterial and venous thromboembolism. In the prevention of all these thromboses and embolisms, anticoagulants, inhibitors of platelet aggregation, as well as agents that increase endothelial thrombosis resistance and improve blood rheology, play a leading role, and in the treatment of already formed thrombi, thrombolytics in combination with anticoagulants and antiaggregants.
Based on the foregoing, it is clear that the success of the operation depends on how accurately the hemostatic status of the organism is established, on the preparedness of the patient for surgical intervention. The effectiveness of the preoperative examination is entirely determined by the joint coordinated work of the attending physician and the doctor of the clinical diagnostic laboratory.
The meaning of a high-quality preoperative coagulogram is seen in determining not individual trends – a decrease or increase in fibrinogen, the detection of a hyper- or hypocoagulation shift, which in itself is not sufficiently informative, but diagnostics based on known algorithms for the most common syndromes in the clinic, selection of patients for grouping the risk of developing postoperative thromboembolism, monitoring the conduct of antithrombotic, anticoagulant therapy, identifying the risk of bleeding, etc. In other words, the laboratory is faced with the task of finding, with the help of a minimum number of tests, the shortest path to a diagnosis, abandoning the little useful one-type examination of patients with different types of pathology.
And so, the initial preoperative examination of the patient includes a set of tests showing how likely the development of a thrombotic or hemorrhagic complication in the examined patient and what preventive measures or additional studies are needed.
Bleeding risk assessment
TEST | NORM | DEVIATION |
Blood platelet count | (150 – 370)*10 9 /l | <100*10 9 /l – hemorrhagic manifestations |
Bleeding time | 5-8 min | extended |
APTT (APTT) | 25 – 35 from | extended |
Prothrombin time | 11-15 from | extended |
Plasma fibrinogen | 2 – 4 g/l | reduced |
Thrombosis risk determination
TEST | NORM | REJECTION |
RFMK in plasma according to the ortho-phenanthroline test | 3. 0-4.0 mg% | more than 10 mg% |
Antithrombin III activity | 80 – 120% | <80% - high risk of thrombosis |
Protein C | 70 – 130% | <70% - high risk of thrombosis |
Factor Va resistance to protein C | NO >0.8 | <0.8 - high risk of thrombosis |
Presence of lupus anticoagulant (Rapid lupus test) | 0.7 – 1.19 | 1.2 -1.29 doubtful result more than 1.3 positive result |
A competent doctor in a diagnostic laboratory is the first assistant to a surgeon. What is not visible to the eye, those processes that have not yet given clinical signs of pathology, have already manifested themselves in laboratory tests. The CDL doctor does not see the patient, but he can very accurately characterize his hemostatic status. Here, the attending physician is required to correctly formulate the task – the purpose of the examination. Be sure to indicate the presence of hemorrhagic (nose, uterine or other bleeding), and / or thrombotic manifestations. Give information about the ongoing treatment that can affect the parameters of hemostasis, their dosages and the timing of the last administration. This information will allow you to make a correct conclusion. If abnormalities are detected in screening tests, a decision is made on preventive preoperative measures or on the need for additional laboratory testing to clarify the cause of coagulation abnormalities. Let us consider in more detail the clinical interpretation of the indicators of the main tests.
Determination of the platelet count
During surgical operations complicated by bleeding, disturbances in the system of vascular-platelet hemostasis in most cases are caused not by a violation of aggregation or other functional properties of platelets, but by the presence of thrombocytopenia of one degree or another (see Table 1). Normally, these cells live in the body for 7-10 days. A decrease in the number of platelets can occur due to many processes.
Reduced platelet production cause adenovirus infections, some antibiotics, liver diseases, ionizing radiation, megaloblastic anemia, tumor diseases, hereditary pathologies of platelet formation (Fanconi, Wiskott-Aldrich, Bernard-Soulier syndromes, May-Heglin anomaly). Increased destruction of platelets occurs in autoimmune diseases, prosthetic heart valves, extracorporeal circulation. The number of platelets can decrease sharply when they are intensive consumption with DIC, thrombotic thrombocytopenic purpura. It should be borne in mind that in women during menstruation, the number of platelets can decrease up to 25-50%.
Activated partial thromboplastin time (APTT)
This is the most valuable of the general tests, revealing exclusively plasma defects in the intrinsic factor X activation system. Prolongation of APTT indicates the predominance of hypocoagulation. For all cases of detecting an extended APTT, an additional examination is necessary to establish the cause and choose methods for correcting and preventing possible bleeding.
Prolongation of APTT with normal prothrombin and thrombin time is observed only with deficiency or inhibition of factors VIII, IX, XI, XII, as well as prekallikrein and kininogen.
Corrective tests are performed in the laboratory for differential diagnosis. When confirming the deficiency of any factor, it is necessary to evaluate its activity in%. To perform operations, the minimum hemostatic level of factors VIII, IX, XI is 25%, with a lower activity of one of the factors, the risk of postoperative bleeding is extremely high.
In the absence of a positive result in corrective tests, an examination for the detection of lupus anticoagulant is necessary.
Deceleration of coagulation (both APTT and prothrombin test ) is observed with a deficiency of X, V, II factors, and under the influence of indirect anticoagulants.
Prolongation of APTT, prothrombin and thrombin time is observed with deep hypofibrinogenemia, treatment with fibrinolysis activators and during treatment with heparin. It is known that patients can be with increased and decreased sensitivity to heparin. To resolve the issue of tolerance to heparin, the APTT is re-determined 1 hour before the next injection. If the APTT is more than 2 times higher than normal, hypersensitivity is noted.
Determination of soluble fibrin (RF or RFMK)
The end result of blood clotting is the known thrombin-induced transformation of fibrinogen into fibrin. In a number of pathologies characterized by intravascular coagulation (DIC, thrombosis, thrombophilia), an increased amount of intermediate products of fibrinogen transformation into fibrin circulates in the blood – fibrin monomer and its oligomers, referred to as soluble fibrin (RF) or soluble fibrin-monomeric complexes – RFMK. Determination of an increased amount of soluble fibrin in plasma is of great diagnostic value, since this protein is a marker of thrombinemia and intravascular coagulation.
Paracoagulation tests, ethanol and protamine sulfate, have traditionally been used to detect MFMC in the clinic. However, they are not informative enough, give false positive results in hyperfibrinogenemia and false negative in hypofibrinogenemia, and only qualitatively reflect the process of transformation of fibrinogen into fibrin. Many researchers consider these tests obsolete and out of use. In recent years, a paracoagulation ortho-phenanthroline test (PT) has been developed and widely used, reflecting the content of soluble fibrin in plasma and the presence of thrombinemia. Approbation of this test in many laboratories has shown that FT allows quite reliably not only qualitatively, but also quantitatively determine the content of soluble fibrin in plasma, including in the conditions of express diagnostics. This opened up prospects for a more accurate assessment of the severity of intravascular coagulation and dynamic monitoring of the effectiveness and sufficiency of therapy for DIC and thrombosis.
Prothrombin test
The synthesis of prothrombin complex factors occurs in the liver with the participation of vitamin K. Indirect anticoagulants inhibit the final stage of synthesis in hepatocytes (carboxylation) of vitamin K-dependent coagulation factors. The efficacy and safety of AEDs are monitored by the indications of a standardized prothrombin test, which should be performed taking into account the sensitivity index of the thromboplastin used in the test (ISI) to depression of prothrombin complex factors. Currently, the Russian Federation produces several thromboplastins standardized according to ISI, which is indicated on the packages of this reagent. For different thromboplastins, this index varies from 1.1 to 1.5, which is taken into account when calculating the international normalized ratio (INR), which guides when choosing the right doses of AED. INR is calculated using the following formula:
INR = (PV of patient plasma/ PV of control normal plasma) ISI
. Currently, a number of countries produce coagulometers that immediately give the result of a prothrombin test for INR. This greatly simplifies the control of dosages of AEDs, allows you to more often evaluate the effect of these drugs, avoiding their overdose.
Antithrombin III activity
It should be taken into account that the anticoagulant and antithrombotic effects of heparins are realized by their complex connection with plasma antithrombin III (AT III). Therefore, with a deep deficiency of AT III, the effect of these drugs is sharply reduced, which is observed in thrombophilia due to AT III deficiency and in some consumption coagulopathy. This decrease in the effectiveness of heparins can be temporarily reversed by transfusions of fresh frozen plasma that contains AT III, or by intravenous administration of AT III concentrate.
To conduct a full-fledged preoperative coagulological examination in each health facility, there is no need to purchase extra expensive equipment and reagents. Today, domestic manufacturers produce high-quality modern devices and diagnostic kits for the study of all parameters of the hemostasis system. Two-channel programmable optical-mechanical coagulometers Minilab 701 and Minilab 704 are currently operating in more than 300 clinics in the country. The well-known in our country and CIS analyzers of platelet aggregation Biola LA 230 allow you to get complete information about the functional activity of platelets based on the results of spontaneous and induced aggregation, study of the factor Willebrand, counting the number of platelets, determining the platelet shape factor. All devices are open to reagents from both domestic and foreign manufacturers, which gives Russian laboratories ample opportunities for accurate and timely diagnosis of hemostasis parameters, especially if an operation is to be performed…
First blood | Such Cases
- Chronic and incurable diseases
- Drama
- How it works
-
05. 08. 2020
Even doctors sometimes make mistakes in orphan diseases. Patients sound the alarm themselves, look for specialized specialists, get themselves referrals for tests, control their performance, delve into the reasons, and discuss their prospects in thematic communities on VKontakte. “Takie Dela” figured out what to do and what to expect if you live in Russia and have a rare disease – ITP, primary immune thrombocytopenia
Sudden death is not worth waiting for – before bleeding in the gastrointestinal tract or brain, hematomas appear on the body, all mucous membranes bleed, platelets fall below 10 thousand. “These situations develop quickly and always require emergency hospitalization. That is why the goal of treating a patient with ITP is to achieve a stable, safe platelet level (>30-50 thousand),” explains Dr. Zotova. But sometimes the disease immediately starts with serious blood loss.
“Wouldn’t have saved anyone”
“I had a sudden uterine bleeding, I was admitted to the hospital – and they found a decrease in platelets. They put me on hormone therapy, it helped only while I was taking the pills. I took a break, went to rest, when I returned, I already had bruises and 7 platelets. The doctors insisted [on the removal of the spleen], I removed it. She went into remission for two years, platelets were 80-120. By that time I was already married and wanted a child. At the fifth month of pregnancy, platelets dropped to 10 thousand, there was a risk of fetal loss. If bleeding had happened, no one would have been saved, ”says Valeria.
After giving birth, she needed to continue taking hormones, but she couldn’t: the side effects were too tormenting. “I had a “lunar” [edematous] face, a [fatty] hump, everything was swollen, my joints hurt. When I stopped taking the pills, it all went away. It was my decision, I myself found a cancellation scheme on the Internet and canceled.
It is possible not to be treated and hope that there will be no next exacerbation, but not for long. Valeria stayed without drugs for two years, and then again ended up in the hospital with uterine bleeding: “I lost a lot of blood, I had zero platelets. I lost consciousness, I vomited, I could not get up. Clots came out of me. It was scary. I could not come to my senses, I fell. I was shaking, my blood pressure was high. They took me away in an ambulance.” Now Valeria is being treated, observed and is waiting for remission. This is the best thing a person with ITP can do.
“Wait”
ITP cannot be cured. You can only maintain a safe level of platelets – for everyone it is different. Synthetic hormones are the first line of therapy. Their job is to suppress the immune system. The second line (for those who have not been affected by the first line) triggers the natural hormone responsible for the production of platelets, thrombopoietin, by interacting with its receptor. These drugs are called thrombopoietin receptor agonists and work in 85-90 percent of patients. The unresponsive 10 percent have their source of immune cells, the spleen, removed. Both methods have serious side effects: bacterial and viral infections stick to the body deprived of the spleen, the use of agonists in some cases excludes pregnancy, since the drugs are harmful to the fetus. But it was agonists, according to Dr. Zotova, that “made a revolution” in the treatment of chronic ITP. “Some patients (about 30 percent) on agonists go into remission, free of therapy, when platelets are kept at a safe level, nothing bleeds, and treatment can be stopped without resorting to long-term hormone therapy and preserving the spleen,” explains the doctor.
Agonists are expensive and given to patients at a discount. That is why hormones are considered the first line of therapy. The president of the All-Russian Society of Hemophilia, lawyer Yuri Zhulev, is sure that the problem is that the regional authorities are responsible for drug provision. “In the regions they often proceed from the financial component. It is easiest to first treat with hormones, then remove the spleen, and only then, if problems continue, transfer to this group of drugs [agonists]. Patients are actively encouraged to remove the spleen,” says Zhulev.
Abrupt withdrawal of agonists and hormones is life threatening. But sometimes nothing depends on the patient. “We had a delay with our [health] department, the drug was not supplied. The child was without treatment for a month. And [try] to explain to our doctors. They said: “Wait.” How can she wait? God forbid, internal bleeding, ”says Kira’s mother Elena.
“It’s completely illegal”
The health of a person with ITP is directly related to geography. According to Zhulev, there are practically no problems in economically prosperous regions, while in poorer regions, patients are forced to beat out vital drugs for themselves through the courts. As a result, local authorities often purchase the drug at a minimum – for reporting, so that it lasts for a couple of months. People who have been on hormones all this time and have been treated with everything they have at hand start saving the drug by reducing dosages, and you can forget about high-quality treatment and the chances of remission.
Sometimes the problem is not even that the agonist is not in the pharmacy, but that a prescription has not been issued for it: the electronic system simply will not allow this if the drug has not arrived at the warehouse. Zhulev calls this a violation of the law and advises in such cases to complain to the regional Ministry of Health, Roszdravnadzor, the prosecutor’s office, and patient organizations. If it doesn’t work, sue. “We are citizens of one country, and laws should be the same for everyone. Interruptions or refusal of treatment is a terrible, very hard life, ”says the lawyer.
Left: View from Elena’s room in her parents’ apartment in Krasnoyarsk. Right: Elena, Krasnoyarsk
Photo: Tatyana Tkacheva for TD
Zhulev is sure that money for agonists should be allocated from the federal budget, this is the only way to reduce the cost of drugs. To do this, it is necessary that ITP be included in the program of high-cost nosologies [state funding of the most expensive treatment], according to which the Ministry of Health of the Russian Federation holds centralized auctions every year with a nationwide volume of purchases. There are far more reasons to demand low prices than in regions with two or three patients. There is no decision yet to include ITP in the program, but the lawyer and his colleagues do not give up: “We have repeatedly appealed [to the president] and hope for him. ITP, unfortunately, did not fall into either the first or the second wave of expanding the list of high-cost nosologies. The arguments are as follows: there are many adults among the patients, and we have an emphasis on children. But adults also deserve the right to a quality life.”
“I had to get myself analyzed”
“It is not clear how long you have to live with this sore. If we don’t know the cause, then we don’t know how serious it is. <...> It is expensive for [government clinics] to buy reagents for analysis. I did a lot of tests for my own money,” says Maria* from Krasnoyarsk. “I had to get myself an analysis for a bone marrow puncture from the thigh, because my local hematologist did not want to send me for this procedure.” Primary immune thrombocytopenia is a diagnosis made “on the contrary”, excluding all other causes of a drop in platelets, from HIV and hepatitis C to rheumatoid arthritis, SLE [systemic lupus erythematosus affecting connective tissues] and oncology. These studies are prescribed in the National Clinical Guidelines for the Diagnosis and Treatment of ITP in Adults and are required by everyone under the CHI policy, but in reality, success again depends on the region and the doctor.
Yury Zhulev explains how and why to defend his right to free tests: “Even if there is no opportunity to carry out any diagnostics in the region, the authorities have two ways: they can sign an agreement with a commercial structure and send patients there, paying for their analysis , or within the framework of the CHI system, send the patient to another region or to the federal center, also paying for such a study. You can complain to your insurance medical organization [its name can be found in the territorial CHI fund], Roszdravnadzor, call the free hotline of the All-Russian Hemophilia Society. Our task is to pose problems and insist on their solution, and then reagents will appear.
***
“You won’t convince me that everything is bad,” this is how Yury Zhulev answers the question of why everything looks so hopeless in the case of ITP. – The way to solve this problem is clear: federalization. The example of other diseases shows that where it occurred, the problem generally goes away. If treated, fully provided with medicines, then people can live a decent life. I am sure that if you take an active position, you can achieve change.”
In anticipation of changes, you can knock on the ITP chat: ask for advice, ask for contacts of familiar specialists and just talk out when things are bad, scary and nothing is clear. There, among the photos of lilac-black bruises, there are stories of remissions.