Hematocrit Testing: Purpose and Procedure

Written by Sarah Vallie

Medically Reviewed by Jabeen Begum, MD on November 09, 2022

• What Is the Hematocrit Test?
• Hematocrit Test Purpose
• Hematocrit Test Procedure
• Hematocrit Test Results

You need blood to carry oxygen through your body, remove carbon dioxide, and fight infection. To do this, your blood has different types of blood cells that do different jobs. If the levels of any of these blood cells are off, it can cause a host of problems for your body. A hematocrit test tells your doctor if your levels of red blood cells are off.

A hematocrit test (HCT test), sometimes called a packed cell volume test (PCV test), is a test that measures your hematocrit. Hematocrit is the level of red blood cells within your blood.

Your blood is made up of plasma and blood cells. Plasma is the liquid part of your blood and is made of protein, salts, and water. Over half your blood composition is plasma.

Suspended in that plasma are three types of blood cells:

• Platelets, also called thrombocytes, are small fragments that help your blood form clots so you stop bleeding.
• Red blood cells are the most abundant type of blood cell in your blood. They’re round with a slightly indented center and contain a protein called hemoglobin. Hemoglobin carries oxygen and removes carbon dioxide.
• White blood cells are part of your immune system. These cells are round with a distinct center. Their job is to fight off unknown invaders by producing antibodies.

Hematocrit tests measure how much of your blood is red blood cells and determine if that amount is normal.

Hematocrit tests are sometimes done as part of routine blood tests, but your provider may order them if they suspect you have a red blood cell disorder. Your red blood cell levels may also be checked before you have surgery. 

A red blood cell count outside the normal range can mean you have a disease or disorder. A low number of red blood cells is called anemia, while having too many red blood cells is called polycythemia.

Anemia. When you’re anemic, you don’t have enough red blood cells to carry oxygen to your tissues. 

There are several different types of anemia. The most common type is iron deficiency anemia. Your bone marrow produces blood cells, and it needs iron to make hemoglobin. If you’re lacking iron, your body can’t produce enough hemoglobin for your red blood cells. This type of anemia is common in pregnant women and people who have experienced blood loss.

Other types of anemia include:

• Anemias associated with bone marrow disease. Diseases, such as cancers like leukemia and myelofibrosis, can affect your bone marrow and may cause your bone marrow to underproduce blood cells. 
• Anemia of inflammation. Some types of inflammatory diseases, including cancer, Crohn’s disease, HIV/AIDS, kidney disease, and rheumatoid arthritis, can interfere with your body’s production of red blood cells.
• Aplastic anemia.Aplastic anemia is a rare but life-threatening type of anemia in which your body doesn’t produce enough red blood cells. It can be caused by autoimmune diseases, infections, medicines, and toxins.
• Hemolytic anemias. Hemolytic anemias happen when your red blood cells are destroyed faster than your body can replace them. You can be born with inherited hemolytic anemia, or you can acquire hemolytic anemia from some autoimmune disorders, cancers, infections, medicines, tumors, and viruses. Hemolytic anemia can also be acquired from an overactive spleen, a reaction to a blood transfusion, or a mechanical heart valve.
• Sickle cell anemia.Sickle cell anemia is a genetic condition in which the red blood cells form a crescent, or sickle, shape due to defective hemoglobin. These oddly shaped red blood cells die quickly, causing your body to always be lacking enough red blood cells.
• Vitamin deficiency anemia (pernicious anemia). Your body also needs vitamins, especially vitamin B12 and folate (B9), to produce healthy red blood cells. A lack of these vitamins, or inability to absorb B12, can cause your body to be unable to produce the red blood cells you need.

Symptoms of anemia may include:

• Chest pain
• Cold hands and feet
• Dizziness or lightheadedness
• Fatigue
• Headaches
• Irregular heartbeat
• Pale or yellowish skin
• Shortness of breath
• Weakness

Polycythaemia. Polycythaemia, also called erythrocytosis, is caused by too many red blood cells, which can cause your blood to become thicker and travel slower through your blood vessels and organs. There are two types of absolute polycythemia, which means polycythemia caused by the overproduction of red blood cells: polycythemia vera (PV) and secondary polycythemia. 

Polycythemia vera is a rare, slow-progressing bone marrow cancer. Most of the time it’s caused by a mutation on the JAK2 gene, a gene within the stem cells of bone marrow. This mutated gene tells your stem cells to reproduce constantly, The new cells also reproduce and, because they have this damaged gene, continue to reproduce until the abnormal cells overwhelm the normal cells. Most people are not born with this mutation; it happens sometime during your life, although doctors don’t know what causes it.

Secondary polycythemia happens when your body produces too much erythropoietin, a hormone made by the kidneys that tells your bone marrow to produce red blood cells. This can be caused by a problem with the kidneys, such as a tumor. It can also be caused by conditions that prevent your body from getting oxygen, like chronic obstructive pulmonary disease (COPD) and sleep apnea.

There are also conditions that cause your hematocrit level to rise because of too little plasma. These include apparent polycythemia and relative polycythemia. Apparent polycythemia is a lack of plasma that can be caused by drinking too much alcohol, smoking, and taking certain medications. Relative polycythemia happens when dehydration causes a lack of plasma.

Symptoms of polycythemia may include:

• Bleeding problems like excessive bruising or bloody noses
• Blurry vision
• Confusion
• Dizziness
• Gout
• Headaches
• High blood pressure
• Itchy skin
• Red skin
• Stomach discomfort
• Tiredness

Both anemia and polycythemia can become life-threatening.

The hematocrit test is done like any other blood test. The lab will likely draw blood from a vein in your arm or hand. To determine your hematocrit, the lab spins your blood sample at a high speed. This causes the plasma and blood cells to separate, and the heavier red blood cells sink to the bottom of the tube. The amount is measured to calculate what percentage of your blood is red blood cells.

Normal ranges of hematocrit can vary depending on your age, race, and sex. Generally, normal ranges are considered to be:

• For adult men, 38. 3%-48.6%
• For adult women, 35.5%-44.9%
• For newborns, 45%-61%
• For infants, 32%-42%
• For kids, 30%-44%

Some factors can cause abnormal hematocrit results despite no underlying disease. These include: 

• Living at a high altitude
• Pregnancy
• Recent blood transfusion
• Severe dehydration
• Severe recent blood loss

If your results come back and your hematocrit is abnormal, your doctor may order further testing to find the cause.

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Hematocrit (HCT) | Ulta Lab Tests

The Hematocrit (HCT) test contains 1 test with 1 biomarker.

Description: The Hematocrit test is a blood test used to measure the percentage of red blood cells in your blood, usually for determining anemia.

Also Known As: HCT Test, Crit Test, Packed Cell Volume Test, PCV Test

Collection Method: Blood Draw

Specimen Type: Whole Blood

Test Preparation: No preparation required

When is a Hematocrit test ordered?

A full blood count usually includes a hematocrit measurement. It can also be ordered as part of a general health assessment, either by itself or in conjunction with a hemoglobin level. When a person develops signs and symptoms of a disorder that affects RBCs, such as anemia or polycythemia, these tests are frequently done.

When someone has signs and symptoms of severe dehydration, such as intense thirst, dry mouth or mucous membranes, and a lack of perspiration or urination, a hematocrit may be requested.

When someone has been identified with recurrent bleeding difficulties, anemia, or polycythemia, this test may be repeated numerous times or on a regular basis to check the success of treatment. It may also be ordered on a regular basis for persons receiving therapy for cancers that affect the bone marrow.

What does a Hematocrit blood test check for?

A hematocrit is a test that determines the percentage of red blood cells in a person’s blood. RBCs, white blood cells, and platelets are suspended in plasma, a fluid component of blood. The hematocrit is a ratio that compares the volume of red blood cells to the volume of all of these components together, which is known as whole blood. A percentage or fraction is used to express the value. A hematocrit of 40%, for example, indicates that there are 40 milliliters of red blood cells per 100 milliliters of blood.

The hematocrit is a quick and easy approach to assess a person’s red blood cells and screen for disorders like anemia. It’s frequently done in conjunction with a hemoglobin level, and it’s also a part of a complete blood count, which is commonly used to assess a person’s overall health.

RBCs are made in the bone marrow and discharged into the bloodstream when they are fully mature or almost so. They normally constitute about 37 to 49 percent of the blood volume. Hemoglobin, a protein that binds to oxygen, is found in RBCs. RBCs’ main job is to transport oxygen from the lungs to the body’s tissues and organs. They also transfer a little amount of carbon dioxide from tissues and organs back to the lungs, where it is exhaled.

RBCs have a 120-day lifespan, and the bone marrow must constantly manufacture new RBCs to replace those that have aged and degraded or have been lost due to hemorrhage. A variety of disorders can impact the bone marrow’s ability to produce new RBCs or the longevity of those already in circulation, as well as cause substantial bleeding.

The hematocrit measures both the number and volume of red blood cells. The hematocrit will drop when the size of the RBCs decreases, and vice versa. In general, the hematocrit will rise as the number of red blood cells increases, and it will fall to less than normal when the number of RBCs produced by the bone marrow decreases, the number of RBCs destroyed increases, or blood is lost due to hemorrhage. The overall amount of RBCs and hematocrit will diminish if the bone marrow is unable to manufacture new RBCs quickly enough, resulting in anemia.

Anemia is a condition in which the body is unable to provide adequate oxygen to tissues and organs, resulting in weariness and weakness. Too many RBCs are created in polycythemia, and the blood thickens, causing sluggish blood flow and other complications.

Lab tests often ordered with a Hematocrit test:

• Hemoglobin
• RBC Count
• Blood Smear
• Iron Total
• Iron and Total Iron Binding Capacity
• Ferritin
• Reticulocyte Count
• Vitamin B12
• Folate
• Complete Blood Count (CBC)
• G6PD
• Erythropoietin
• Hemoglobinopathy Evaluation

Conditions where a Hematocrit test is recommended:

• Anemia
• Sickle Cell Anemia
• Thalassemia
• Myeloproliferative Neoplasms
• Bone Marrow Disorders

How does my health care provider use a Hematocrit test?

The hematocrit test is frequently used to diagnose anemia, usually in conjunction with a hemoglobin test or as part of a full blood count. The test can be used to detect, diagnose, or track a variety of illnesses and disorders that impact the amount of red blood cells in the blood. RBCs are red blood cells that circulate in the blood and transport oxygen throughout the body.

Some circumstances influence RBC formation in the bone marrow, resulting in an increase or decrease in the number of mature RBCs discharged into circulation. The longevity of RBCs in the circulation may be affected by other factors. The overall number of RBCs and hematocrit will diminish if there is increased destruction or loss of RBCs, and/or the bone marrow is unable to make new ones quickly enough, leading in anemia.

The hematocrit can tell if there’s a problem with RBCs, but it can’t tell what’s causing it. A blood smear, reticulocyte count, iron studies, vitamin B levels, and, in more severe cases, a bone marrow examination are some of the other tests that may be conducted at the same time or as follow-up to establish a reason.

What do my Hematocrit test results mean?

Red blood cells make up between 37 percent to 49 percent of the total amount of blood.

Because a hematocrit is frequently performed as part of a complete blood count, other components including RBC count, hemoglobin, reticulocyte count, and/or red blood cell indices are taken into account. Other considerations include age, gender, and race. In general, the hematocrit reflects the RBC count and hemoglobin readings.

Anemia is diagnosed by a low hematocrit, low RBC count, and low hemoglobin.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

What tests to pass to the child, children’s tests in St. Petersburg

Blood, urine and stool tests allow doctors to find out what is happening in your child’s body. Whether it’s assessing general health, preventing serious illnesses, preparing for kindergarten or summer camp. Childhood tests are an important diagnostic tool. On this page we have collected most requested tests for children .

Please note that the information provided on this page is for informational purposes only. Before taking any tests, we recommend that you consult with your child’s primary care physician, pediatrician, or other specialist you plan to visit.

Complete (clinical) blood test with ESR

Clinical blood test is prescribed by a doctor to assess the general condition of the child’s body, to confirm certain diagnoses and screen for current diseases. When calculating the leukocyte formula , parameters such as the number of red blood cells, white blood cells, platelets and the ratio of blood cells to plasma (hematocrit) are monitored. This test is one of the most important blood tests for children.

The complete blood count includes a test for hemoglobin , a protein present on the surface of red blood cells that carries oxygen to various parts of the body. It contains iron, which is essential for the production of this protein in the body. The hemoglobin level is an important indicator because it allows doctors to know if a child has iron deficiency anemia. If a child suffers from chronic weakness, pale nails, or skin depigmentation, a doctor may recommend this test. The hemoglobin test, together with the hematocrit levels from the CBC, helps the pediatrician assess the child’s iron levels.

• General (clinical) blood test with ESR

Biochemical blood test

This complex contains very important studies that are direct markers of liver and kidney function. They also give an idea of ​​the acid-base balance of the body and the buffer systems of the blood, which maintain the required level of salts at an optimal level. All this will give the pediatrician a complete picture of the state and functioning of your child’s body.

• Biochemical blood test (advanced)

Blood type and Rh factor test

Every person’s blood cells have specific markers called antigens on their surface. These antigens are classified into four different types according to the ABO blood group system. The different antigens are A, B, AB, and O. Based on these antigens, four blood types are distinguished in humans. Another important antigen that helps classify blood types is the Rh antigen, and depending on its presence, a person can be either Rh positive or Rh negative. Almost 80% of the world’s population are Rh-positive, and the rest do not have this antigen. Blood typing is one of the most important blood tests for children. This information may be needed in the case of blood transfusions and for surgical interventions, to predict the development of certain diseases, in the preparation of medical documents and to ensure the safety of the mother and child in the event of a mismatch of the Rh antigen.

• Blood group and Rh factor

Glucose test

Glucose level in the blood is an important marker of diabetes and a mandatory blood test for both children and adults. Most children diagnosed with diabetes have type I diabetes. This condition is caused when the immune system destroys the insulin-producing alpha cells in the pancreas. Although the reason for this behavior is not completely clear, it is believed that hereditary and genetic factors are responsible for this. The lack of insulin causes the concentration of glucose in the blood to rise, while it is not drawn into the cells for use as energy. This causes long-term complications and is compensated by periodic injections of insulin. In rare cases, children are also diagnosed with type II diabetes. This increase in the incidence of type II diabetes at an early age is believed to be due to unhealthy lifestyles, bad habits and reduced physical activity. The attending pediatrician may prescribe blood sugar tests for your child if diabetes is suspected.

• Glucose (plasma)

Allergy Blood Tests, Allergy Panels

Although skin testing is the preferred form of allergy testing, it is blood tests that are used when a pediatrician suspects serious allergic reactions in infants and young children.

There are two types of allergy blood tests :

1. Detection of specific antibodies in the blood called immunoglobulins E or IgE that are associated with allergic reactions.
2. Detection of an increase in the level of specific allergic leukocytes, such as eosinophils.

• Pediatric allergen complex
• Baby Food Allergen Mix
• Pre-vaccination panel (vaccine components)
• Eosinophilic cationic protein (ECP)

Lipid profile

Until recently it was thought that this test was not required for children. However, the modern lifestyle has made its own adjustments: more and more foods high in sugar appear in the diet, and cases of childhood obesity have become more frequent. Therefore, even children are now considered at risk for high cholesterol levels .

Certain types of cholesterol can increase the risk of heart disease and make life difficult. Lipid profile measures the amount of high density lipoprotein (good cholesterol), low density lipoprotein (bad cholesterol), total cholesterol and triglycerides (freely present fats) in the blood, as well as the atherogenic ratio. These tests help doctors determine the potential risk of cholesterol to your child’s health.

Not tested in children under two years of age and in adolescents during puberty due to fluctuations in lipid levels. For children of other age groups, this study is being conducted.

• Lipidogram (lipid profile)

Tuberculosis testing

Tuberculosis screening tests are especially important for children who may have a compromised immune system or for those who have been in contact with an infected person. Blood tests for tuberculosis are usually prescribed after skin tests, but it is possible to replace the Mantoux or Diaskintest reactions with them. Blood tests for TB tell whether a child is infected with TB bacteria, not if the disease is active.

Please note that once the blood test is positive for TB, further testing will be required to determine if the child has an active TB infection.

• T-SPOT – diagnosis of tuberculosis infection
• Quantiferon test (tuberculosis diagnosis)

Fecal tests for helminths and protozoa

The results of a stool test can provide the physician with valuable information about a child’s gastrointestinal problems. The doctor may order a test if the child has symptoms of a possible parasitic infection, such as restless sleep, itching in the perineum, diarrhea for a long period of time, blood or mucus in the stool, abdominal pain, nausea, headaches, or fever, especially if an outbreak of a parasitic disease has been recorded in a school or kindergarten.

Microscopic examination of helminth eggs and protozoa detects parasites, their eggs or cysts, which are hard shells that protect some parasites at a certain stage of their life cycle.

PCR testing is extremely sensitive as it requires only a small amount of parasite DNA in a stool sample to produce a positive result, and very specific as it only detects parasites included in the test system. PCR testing can be recommended both as a stand-alone study for suspected specific parasites, and as an additional to confirm the results of microscopic analysis.

• Scraping for enterobiasis
• Test for helminth eggs
• Test for helminth eggs and protozoa (cumulative, preservative)
• PCR-complex Helminths (Ascarids, Wide tapeworm, Opisthorchiasis, Pork tapeworm)
• PCR complex Helminths + Protozoa (Ascarids, Blastocysts, Cryptosporidium parvum, Lamblia)

Test for intestinal infections

Infections of the gastrointestinal tract can be of viral, bacterial or parasitic origin, cause gastroenteritis, an inflammation of the gastrointestinal tract that affects the stomach, small and large intestines. The typical clinical symptoms are almost identical and include diarrhea, vomiting, and abdominal pain. Thus, it is difficult to determine the pathogenic cause of the disease in time only on the basis of clinical signs. At the same time, the rapid selection of an effective method of treatment in some cases may be of paramount importance for the life of the patient.

According to WHO, diarrhea is the second leading cause of death in children under five years of age, with 525,000 deaths each year. Diarrhea can last for several days and can deplete the body of water and salt needed to survive.

Rapid diagnosis of acute gastrointestinal infections in the Explan laboratory includes tests for 8 bacterial and 9 viral pathogens. The result is issued on the day of the analysis (subject to delivery before 12.00).

• Rapid diagnosis of acute gastrointestinal infections

Complex of tests for kindergarten and school

Complex of analyzes for kindergarten and school will help assess the general condition of the child’s body, make sure that the child is ready to visit the pool, kindergarten, the new academic year or the children’s camp, identify diseases in the early stages and to diagnose latent infectious diseases.

This package includes all necessary laboratory tests. This complex greatly simplifies and speeds up the process of medical examination of the child.

• Complex of tests for kindergarten and school (Clinical blood test + ESR + Leukocyte formula + Urinalysis with sediment microscopy + Feces for helminth eggs + Scraping for enterobiasis + Glucose)

Related research

700 rub.

#01-01-01

Complete clinical blood test with ESR and leukocyte formula

Complete clinical blood test (CBC) with leukocyte formula and ESR (with microscopy of a blood smear) is a very important clinical study, which is a fast, affordable and reliable diagnostic method, therefore a complete blood count is mandatory analysis performed during the primary diagnosis

RUB 2090

#01-05-257

Advanced biochemical blood test

Biochemical blood test is a method that allows you to evaluate the work of many internal organs. An extended biochemical blood test includes important indicators that reflect the state of protein, carbohydrate, lipid and mineral metabolism, as well as the activity of key blood serum enzymes. In addition,

520 rubles.

#09-01-124

Blood group and Rh factor

This test will help determine your individual blood type and Rh factor.

An analysis to determine the blood group and Rh factor is recommended for preparation for surgical intervention and / or transfusion of blood and its components, as well as when planning pregnancy, during pregnancy

210 r.

#01-05-22

Glucose (plasma)

Glucose is the main component of energy metabolism in the body.

A decrease in blood glucose levels can be observed with a number of protein metabolism disorders. First of all, this refers to disorders of glycogen metabolism and defects in mitochondrial beta-oxidation, in which glycemia can be the only

RUB 4600

#03-10-111

Allergen complex “Pediatric”

Allergen complex “Pediatric” includes a set of 25 allergens most common in pediatric practice: household, respiratory, food and animals. Specific immunoglobulins E (IgE) are determined in the blood serum.

Indications for prescription may be: rhinitis (sneezing, pawn

560 rubles

#03-11-80_01

Baby food allergen mix, fm101, allergen

Quantification in the blood of specific antibodies, class E immunoglobulins, which appear in the presence of an allergic reaction to a mixture of allergens in baby food (egg white, egg yolk, cow’s milk, rye flour, wheat flour, corn flour, casein, gluten, Cheddar cheese, alpha -lactal

RUB 1450

#09-01-209

Pre-vaccination panel (vaccine components)

This study determines the presence of sensitization to vaccine components and is not a predictor of other pathological reactions to vaccination.

A doctor’s consultation is required.

This complex contains vaccine components:

Yeast (Hepatitis B – Engerix),
ovalbumin (measles, rubella, mumps

RUB 890

#03-04-501

Eosinophilic cationic protein (ECP)

Eosinophilic cationic protein (ECP) is one of the objective markers of allergic inflammation, the level of which determines the degree of damage to the mucous membranes. ECP is associated with the mechanisms of anthelmintic, antibacterial, antitumor, antiviral activity

1090 р.

#01-05-65

Lipidogram

Lipidogram, or lipid profile, is a study that determines the level of lipids in various blood fractions.

Allows you to detect lipid metabolism disorders that play an important role in the development of vascular atherosclerosis. Increased blood cholesterol (hypercholesterolemia) and local inflammation

4500 r.

#03-02-123

T-SPOT – diagnosis of tuberculosis infection

The T-SPOT.TB study is an immunological method for diagnosing tuberculosis, based on measuring the production of γ-interferon by T-lymphocytes in response to stimulation with ESAT-6 and CFP-10 proteins. These tests, called IGRA (interferon gamma release assay), have shown their specificity, since the result

RUB 4950

#03-07-18

TB-feron test (determination of gamma-interferon for MTB antigens (ESAT-6, CFP-10, TB-7. 7) (diagnosis of tuberculosis)

TB-Feron is a diagnostic qualitative in vitro test for tuberculosis infection, which is based IGRA method (interferon-gamma release assay) The test is based on the ability of T-lymphocytes to recognize M. Tuberculosis antigens in the event that a person has already met with an infection and isolate

$440

#01-03-05

Enterobiosis scraping

This is a microscopic examination of a perianal impression smear to detect eggs of Enterobius vermicularis (pinworms).

Enterobiosis is a helminthiasis characterized by abdominal pain, loss of appetite, itching in the perianal and perineal regions.

Excite

390 r.

#01-03-02

Test for helminth eggs

Test for eggs of helminths is a microscopic examination of feces aimed at identifying helminths, their eggs, fragments or larvae.

The causative agents of helminthiases are parasitic worms. In human feces, the eggs of the following helminths are most often found: roundworm, whipworm, t

540 r.

#01-03-03

Test for eggs of helminths and protozoa (cumulative, preservative)

Analysis of feces for eggs of helminths and protozoa is a microscopic examination of feces aimed at identifying helminths, their eggs or larvae, as well as identifying cysts and vegetative forms of protozoa.

The causative agents of helminthiases are parasitic worms. In human feces, the most frequently found

1930

#09-01-53

Complex of Helminths (Ascaris, Broad tapeworm, Opisthorchiasis, Pork tapeworm)

The PCR-complex Helmo-screen (diagnosis of pathogens of helminthiasis) includes the most common parasitic worms that affect the human body and animals, causing helminthiases.
Most often, infection occurs when eggs of parasites are swallowed with food, water, through dirty hands or

2200 r.

#09-01-54

Complex Helminths + Protozoa (Ascarids, Blastocysts, Cryptosporidium parvum, Broad Ribbon, Giardia)

The PCR complex “Helminths + Protozoa” includes the most common parasitic worms and protists, including giardia and roundworm that infect humans and animals.
Most often, infection occurs when eggs of parasites are swallowed with food, water, through dirty hands or household items

1970

#02-06-03_1

Rapid analysis of acute intestinal infections

Express analysis of acute infections of the gastrointestinal tract is performed by PCR and includes the diagnosis of the most common pathogens of the gastrointestinal tract.

Thanks to the PCR method, analysis for a disgroup and viruses is performed in a matter of hours.

To pass the analysis, it is necessary to collect feces

1010 r.

#09-01-139

Complex of analyzes for kindergarten and school

Complex of analyzes for kindergarten and school will help assess the general condition of the child’s body, make sure that the child is ready to visit the pool, kindergarten, the new academic year or the children’s camp, identify diseases in the early stages and diagnose hidden infectious diseases.

Currently

prices, take tests in Moscow near you in the DNAOM laboratory

Complete blood count 5 diff is a study of the qualitative and quantitative composition of blood elements.

The test material is venous blood.

CBC 5 diff includes:

• determination of the size, number, shape of erythrocytes and their hemoglobin content;
• determination of the ratio of plasma volume to blood cells;
• determination of the total number of leukocytes;
• calculation of the percentage of different leukocytes: neutrophils, lymphocytes, monocytes, eosinophils and basophils on an automatic analyzer;
• counting and evaluation of the average size of platelets.

The CBC is performed as the first screening test for complaints of “malaise”. The analysis gives an idea of ​​the possible areas where pathological changes occur and helps the clinician determine further examination tactics.

Indications:
• screening examinations within the framework of preventive, dispensary observation;
• basic examinations during hospitalization in therapeutic and surgical hospitals;
• diagnosis of anemia;
• diagnostics of inflammatory, infectious diseases;
• diagnostics of diseases of the blood system;
• monitoring of ongoing therapy and the course of various diseases.

Preparation
Special preparation is not required. It is recommended to take blood no earlier than 4 hours after the last meal (for children – before the next feeding). If possible, eliminate high emotional and physical stress the day before.

Interpretation of results
When interpreting the analysis, it should be taken into account that in 5% of healthy people, the blood test values ​​deviate from the accepted reference values. Blood counts depend on race and sex, age.

The most important indicators in the general blood test are:


1. Hb (hemoglobin) – hemoglobin;
2. Ht – hematocrit;
3. total number of erythrocytes in ;
4. MCV * — mean erythrocyte volume;
5. RDW * – distribution of erythrocytes by volume;
6. MCH * — average content of hemoglobin in 1 erythrocyte;
7. MCHC * – average concentration of hemoglobin in erythrocytes;
8. total platelet count;
9. total number of leukocytes ;
10. leukocyte formula.

*It should be taken into account that the value is not specific, the indicator should be used to diagnose anemia only in combination with other indicators of the general blood test and biochemical blood test.

Determination of CBC parameters allows diagnosing conditions such as anemia/polycythemia, thrombocytopenia/thrombocytosis and leukopenia/leukocytosis, which can either be symptoms of a disease or act as independent pathologies.

Hemoglobin (Hb, hemoglobin)
A protein in erythrocytes that contains heme. The main function is the transport of oxygen.
Units of measurement: g/l.

Increased hemoglobin level:


• dehydration: with severe diarrhea, vomiting, increased sweating, diabetes, burn disease, peritonitis;
• physiological erythrocytosis: in residents of highlands, pilots, athletes;
• symptomatic erythrocytosis: with insufficiency of the respiratory and cardiovascular systems, polycystic kidney disease; erythremia.

Decreased hemoglobin:


• anemia of various etiologies;
• hyperhydration.

Hematocrit (Ht, hematocrit)
An indicator of the proportion of cells in the majority of red blood cells to the liquid part of the blood.
Units: %

Increase in hematocrit:



• dehydration: with severe diarrhea, vomiting, increased sweating, diabetes, burn disease, peritonitis;
• physiological erythrocytosis: in residents of highlands, pilots, athletes;
• symptomatic erythrocytosis: with insufficiency of the respiratory and cardiovascular systems, polycystic kidney disease;
• erythremia.

Decreased hematocrit:


• anemia of various etiologies;
• hyperhydration.

Erythrocytes
Units: ppm (10 ⁶ /µl).
Alternative units of measurement: 10 ¹² cells/l.
Conversion factors: 10 ¹² cells/L = 10 ⁶ cells/µL = million/µL.

Increase in the concentration of red blood cells:


• dehydration: with severe diarrhea, vomiting, increased sweating, diabetes, burn disease, peritonitis;
• physiological erythrocytosis: in residents of highlands, pilots, athletes;
• symptomatic erythrocytosis: with insufficiency of the respiratory and cardiovascular systems, polycystic kidney disease;
• erythremia.

Decrease in the concentration of erythrocytes:


• anemia of various etiologies;
• hyperhydration.

MCV
Estimated indicator, which is calculated based on the histogram of the distribution by size of erythrocytes. According to MCV, microcytic, normocytic and macrocytic anemias are distinguished. An increase in the indicator indicates the presence of large erythrocytes in the blood, a decrease indicates the presence of small ones.

Units: fl (femtoliter).

Increased MCV values:


• B ₁₂ – deficiency and folate deficiency anemia;
• aplastic anemia;
• liver disease;
• hypothyroidism;
• autoimmune anemias;
• smoking and drinking.

Decreased MCV values:


• iron deficiency anemia;
• anemia of chronic disease;
• thalassemia;
• some types of hemoglobinopathies.

RDW (Red cell Distribution Width)
The calculated value, which is calculated on the basis of the histogram of the distribution of erythrocytes by volume. Reflects the heterogeneity of erythrocyte sizes. An increase in the indicator indicates that small and large red blood cells are present in the blood sample. Decreasing the value indicates the homogeneity of erythrocytes in the sample.

Units: %


Increasing RDW values:



• anemia with heterogeneity in erythrocyte size, including those associated with nutrition; myelodysplastic, megaloblastic and sideroblastic types; anemia accompanying myelophthisis; homozygous thalassemias and some homozygous hemoglobinopathies;
• a significant increase in the number of reticulocytes;
• condition after red cell transfusion;
• interference – cold agglutinins, leukemia, hyperglycemia.

MCH
A calculated indicator that characterizes the average mass of hemoglobin in an erythrocyte. An increase in the indicator is associated with a supersaturation of erythrocytes with hemoglobin, a decrease indicates a deficiency of hemoglobin.

Units: pg (picogram).

MCH increase:



• B ₁₂ – deficiency and folate deficiency anemia;
• aplastic anemia;
• liver disease;
• hypothyroidism;
• autoimmune anemias;
• smoking and drinking.

Decreased MCH:


• iron deficiency anemia;
• anemia of chronic disease;
• some types of hemoglobinopathies.

MCHC
A calculated indicator that characterizes the average mass of hemoglobin contained in a unit volume of an erythrocyte.

Units: g/dl.
Alternative units of measurement: g/l.
Conversion factor: g/l x 0.1 ==> g/dl.

Increase in MCHC values:



• hereditary microspherocytic anemia.

Decreased MCHC values:


• iron deficiency anemia;
• anemia of chronic disease;
• some types of hemoglobinopathies.

It should be borne in mind that the MCHC value is not specific, the indicator should be used to diagnose anemia only in combination with other indicators of a complete blood count and a biochemical blood test.


Platelets
Units: thousand/µl (10 ³ cells/µl).
Alternative units of measurement: 10 ⁹ cells/l.
Conversion factors: 10 ⁹ cells/l = 10 ³ cells/µl = thousand/µl.

Increased platelet concentration:


• physical overexertion;
• inflammatory diseases, acute and chronic;
• hemolytic anemias;
• anemia due to acute or chronic blood loss;
• conditions after undergoing surgical interventions;
• condition after splenectomy;
• oncological diseases and hemoblastoses.

Decreased platelet concentration:


• pregnancy;
• B ₁₂ – deficiency and folate deficiency anemia;
• aplastic anemia;
• viral and bacterial infections;
• taking drugs that inhibit platelet production;
• congenital thrombocytopenia;
• splenomegaly;
• autoimmune diseases;
• conditions after undergoing massive blood transfusions.

Leukocytes
Cells with nuclei that perform protective functions. Formed in the red bone marrow and organs of the lymphatic system. There are 5 populations: neutrophils, lymphocytes, monocytes, eosinophils or basophils. Functions and lifetime depend on which population the leukocyte belongs to.

Units: thousand/µl (10 ³ cells/µl).
Alternative units of measure: 10 ⁹ cells/l.
Conversion factors: 10 ⁹ cells/l = 10 ³ cells/µl = thousand/µl.

Increase in the concentration of leukocytes:


• physiological leukocytosis: emotional and physical stress, exposure to sunlight, cold, eating, pregnancy, menstruation;
• inflammatory processes;
• viral and bacterial infections;
• conditions after surgery;
• intoxication;
• burns and injuries;
• infarcts of internal organs;
• malignant neoplasms;
• hemoblastosis.

Decrease in the concentration of leukocytes:


• viral and some chronic infections;
• taking medications: antibiotics, cytostatics, non-steroidal anti-inflammatory drugs, thyreostatics, etc.;
• autoimmune diseases;
• exposure to ionizing radiation;
• wasting and cachexia;
• anemia;
• splenomegaly;
• hemoblastosis.

Leukocyte formula
Leukocyte formula – the percentage of different types of leukocytes in peripheral blood and counting their number per unit volume.