Hematocrit Information | Mount Sinai

HCT

Hematocrit is a blood test that measures how much of a person’s blood is made up of red blood cells. This measurement depends on the number of and size of the red blood cells.

Blood transports oxygen and nutrients to body tissues and returns waste and carbon dioxide. Blood distributes nearly everything that is carried from one area in the body to another place within the body. For example, blood transports hormones from endocrine organs to their target organs and tissues. Blood helps maintain body temperature and normal pH levels in body tissues. The protective functions of blood include clot formation and the prevention of infection.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary for this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

The hematocrit is almost always done as part of a complete blood count (CBC).

Your health care provider may recommend this test if you have signs of or are at risk for anemia. These include having:

• Before and after major surgery
• Blood in your stools, or vomit (if you throw up)
• Chronic medical problems, such as kidney disease or certain types of arthritis
• During pregnancy
• Fatigue, poor health, or unexplained weight loss
• Headaches
• Heavy menstrual periods
• Leukemia or other problems in the bone marrow
• Monitoring during treatment for cancer
• Monitoring medicines that may cause anemia or low blood counts
• Monitoring of anemia and its cause
• Poor nutrition
• Problems concentrating

Normal Results

Normal results vary, but in general they are:

• Male: 40. 7% to 50.3%
• Female: 36.1% to 44.3%

For babies, normal results are:

• Newborn: 45% to 61%
• Infant: 32% to 42%

The examples above are common measurements for results of these tests. Normal value ranges vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Low hematocrit may be due to:

• Anemia
• Bleeding

• Bone marrow being unable to produce new red blood cells. This may be due to leukemia, other cancers, drug toxicity, radiation therapy, infection, or bone marrow disorders 

• Chronic illness
• Chronic kidney disease
• Destruction of red blood cells (hemolysis)
• Leukemia
• Malnutrition
• Too little iron, folate, vitamin B12, and vitamin B6 in the diet
• Too much water in the body

High hematocrit may be due to:

• Bone marrow disease that causes abnormal increase in red blood cells (polycythemia vera)
• Congenital heart disease
• Exposure to high altitude
• Failure of the right side of the heart
• Low levels of oxygen in the blood
• Scarring or thickening of the lungs
• Too little water in the body (dehydration)

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood buildup under the skin)
• Infection (a slight risk any time the skin is broken)

Chernecky CC, Berger BJ. H. Hematocrit blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:620-621.

Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM. Blood disorders. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 124.

Means RT. Approach to the anemias. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 149.

Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31.

Last reviewed on: 1/9/2022

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

Hematrocit Blood Test – Testing.com

Test Quick Guide

Blood is made up of red blood cells (RBC), white blood cells (WBC), and platelets which are suspended in a liquid called plasma. A hematocrit (HCT) lab test determines the percentage of the blood that is composed of RBC.

An HCT test helps your medical provider screen for, diagnose, and monitor conditions that affect your blood or bone marrow. A measurement of HCT is routinely included in a complete blood count (CBC) but may also be ordered on its own if your provider suspects a condition affecting your RBC.

About the Test

Purpose of the test

The purpose of an HCT test is to evaluate the percentage of blood that is made up of RBC. This measurement indicates the viscosity, or thickness, of the blood and depends on the size and number of RBCs in a blood sample. HCT is most often evaluated as part of a CBC, which also includes measurements of RBC, WBC, platelets, and hemoglobin.

Often ordered during a routine medical check-up, a CBC is a common lab test. A CBC that includes HCT may also be ordered to evaluate the cause of certain symptoms, monitor patients receiving medical treatments, and track those with chronic health issues that affect the blood.

What does the test measure?

HCT measures the proportion of the blood that is composed of RBC and is expressed as a percentage.

RBCs are critical for the distribution of oxygen to the body’s cells. Once oxygen is used by cells to produce energy, RBCs transport the waste product, carbon dioxide, from the cells back to the lungs.

HCT levels can be affected by an increase or decrease in the number of RBCs and by changes in other components of the blood. Because HCT measures the percentage of RBC in the blood, relative increases or decreases in other blood components, like plasma or WBC, can lead to abnormal HCT results even if the RBC count is normal.

When should I get this test?

Your provider may test HCT as part of a CBC or if you are experiencing symptoms of an RBC disorder such as anemia. Indications for testing HCT include:

• Fatigue
• Moodiness
• Headaches
• Brain fog or difficulty concentrating
• Heavy menstrual flow
• Poor nutrition
• Blood in your stools or vomit
• Cancer and cancer treatment
• Excessive diarrhea or vomit
• Leukemia or other conditions associated with bone marrow
• Chronic health conditions, including kidney diseases

Finding an HCT Test

How can I get an HCT test?

An HCT test requires a sample of blood and is typically ordered by a doctor. A blood draw, also called venipuncture, is conducted by a health provider or a laboratory technician in a medical setting.

Can I take the test at home?

HCT testing is not usually performed at home. Conducting this test requires specialized tools and trained laboratory personnel.

How much does the test cost?

The cost of an HCT test depends on several factors, including other tests performed at the same time and whether or not you have health insurance or are paying out-of-pocket. The cost of HCT testing is often covered by insurance due to the routine nature of the test.

Refer to your health care provider, medical facility, or insurance company for specific details on costs, copays, and deductibles.

Taking an HCT Test

A blood sample is needed for HCT testing. To collect a blood sample, a needle is inserted into your arm and a vial, also known as a vacutainer, is placed on the provider’s end of the needle. The vial is then filled with blood that is used to test your hematocrit.

Before the test

There is no special preparation needed prior to an HCT test, unless specified by your provider.

During the test

Blood draws are a common medical procedure. Usually, blood is drawn from either the top of the hand or the vein on the inside of the elbow. To conduct a blood draw:

1. An antiseptic wipe is used to cleanse the area prior to the blood draw.
2. A band is placed around your arm to increase pressure in your vein, making your vein more visible and easier to access.
3. A needle is placed in your vein and a test tube is attached to the needle and filled with blood.
4. If you are getting other blood tests in addition to an HCT test you may have more than one vial of blood drawn.

After the test

Once the blood is drawn, the nurse or phlebotomist may ask you to hold pressure on the site of the venipuncture with a cotton swab for a few minutes. They may place a bandage on the cotton swab to maintain pressure.

After any blood draw, you will want to watch out for temporary side effects such as dizziness or lightheadedness. Your provider may want you to stay seated for a few minutes until they can determine that you are safe to get up and walk or drive.

Other than possible lightheadedness and bruising at the site where blood was drawn, there are few potential side effects from a blood draw.

HCT Test Results

Receiving test results

After the test is complete, results will be sent to your doctor for interpretation. HCT test results are most often part of the results of a CBC, which may be available to your doctor within a few minutes or up to several days.

Interpreting test results

HCT test results depend on several factors, including age and sex. The cutoff values for a normal test result, called its reference range, may also vary depending on the laboratory or methods used to conduct the test. Because of the many factors that affect HCT, it’s important to talk to a doctor for support in understanding your test result.

The reference ranges listed below describe common reference ranges for hematocrit:

Hematocrit Reference Ranges for Adults

An abnormal HCT level can indicate that your blood is either too thin or too thick compared to an average person of a similar population.

An abnormally low level of HCT indicates that your cells may not be getting enough oxygen, a condition known as anemia. Abnormally low HCT may be related to a variety of causes, including:

• Loss of blood
• Poor nutrition with low intake of iron, vitamin B6, vitamin B12 or folate
• Bone marrow disorders or cancers such as leukemia, lymphoma, multiple myeloma, or other cancers that spread to the marrow
• Destruction of RBCs
• Excessive water in the body

High HCT levels indicate conditions where there is either an overproduction of RBC or an abnormally high concentration of RBCs in your body. Some examples of causes of a high HCT include:

• Dehydration
• Lung disease
• Congenital heart disease
• Heart failure
• Certain types of kidney tumors
• Smoking
• Living at high altitudes
• Secondary polycythemia, a rare group of blood disorders caused by heritable changes to genes involved in the production of RBCs causing the body to produce too many RBCs
• Polycythemia vera, a rare blood disease in which the body produces too many RBCs

Although the results are accurate, laboratory parameters and provider reference ranges as well as personal variables may be subject to differences.

Abnormal HCT test results may or may not require additional follow-up testing. HCT is often evaluated alongside other components of a CBC to look for signs of disease or monitor health conditions.

For example, a doctor may order additional testing if you have low HCT to evaluate the cause of anemia. Testing for anemia may include a reticulocyte count, a renal panel, a liver panel, hemolysis testing, or a blood smear.

Follow-up testing is based on your symptoms, medical history, and the results of other tests. For questions about follow-up testing, speak with your doctor.

Talking with your doctor can help you understand your HCT result and any next steps. You may wish to ask the following questions:

• What does my result mean for my health?
• Is there anything I can do to change my HCT levels?
• Is there any further testing that needs to be done based on my HCT levels?

Resources

• CBC Blood Test (Complete Blood Count)
  Learn More
• Red Blood Cell Count (RBC) Test
  Learn More
• Hemoglobin Blood Test
  Learn More
• White Blood Cell Count (WBC Blood Test)
  Learn More
• Platelet Count (PLT) Blood Test
  Learn More
• Blood Smear
  Learn More
• Iron Test
  Learn More
• National Heart, Lung, and Blood Institute: Anemia
  Learn More
• National Heart, Lung and Blood Institute: Thalassemias
  Learn More

Sources

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Laboratory tests – Medical Center “Nadezhda” named after. A.S. Aronovich.

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Any laboratory test gives the doctor additional information to help diagnose and prescribe treatment.

The result of any analysis may contain human or hardware error. Therefore, doctors, in addition to the main tests, prescribe confirmatory or clarifying tests. For example, when diagnosing infections, it is desirable not only to analyze the pathogen (seeding or DNA diagnostics), but also to determine the body’s response to this pathogen (enzyme-linked immunosorbent assay – ELISA, component binding reaction). Therefore, full-fledged laboratory diagnostics implies a specific list (standard) of tests for each disease.

Pre-registration is not required for testing.

How to pass tests for a child and an adult?

To tell you about the details of preparing for the collection of all existing analyzes, you will have to write a thick reference book. Therefore, we confine ourselves to the “main” analyzes, which we pass more often than others.

General rules for donating blood

• blood test is taken strictly on an empty stomach – not earlier than 12 hours after the last meal. Dinner the day before should be light and early, and the entire previous day should refrain from fatty foods;
• any alcohol, thermal procedures (bath and sauna) and physical activity are excluded for 24 hours;
• tests are given before x-rays, injections, massage and medication;
• if repeated examinations are necessary, it is advisable to take blood samples at the same time of day;
• Rest for 5-10 minutes in front of the laboratory door.

When donating blood for glucose , in addition, you should not brush your teeth and chew gum, and morning tea or coffee (even unsweetened) is completely contraindicated. Contraceptives, twenty drops of cognac in evening tea, diuretics and other medicines will also change glucose levels.

Biochemical blood tests

In the study of bile pigments, the picture is distorted by products that cause coloring of blood serum – pumpkin, beets, carrots, citrus fruits. Pork chop the day before will increase the level of potassium and uric acid in the blood.

Blood donation for hormones

Stop all hormonal preparations a month before the examination. When donating blood to determine the level of sex hormones, you will also have to refrain from sex (in any form) and sexual arousal for at least 24 hours. Otherwise, at best, you will have to retake an expensive analysis, and at worst, receive inadequate therapy.

Thyroid hormone testing requires avoiding iodine preparations and avoiding iodized salt.

Complete urinalysis

General clinical urinalysis is the most common analysis in medical practice, along with the general blood test. But, despite this, most patients are not aware that before you write in a jar, you need to wash the external genitalia (necessarily towards the anus, and not away from it) and wipe dry with a clean linen napkin. Further, the first and last portions of urine are drained past the container, and medium for clean dishes . Otherwise, bacteria and mucus with leukocytes from the genitals will enter the urine, and the patient will be treated, for example, for pyelonephritis.

Neglect of hygiene or use of dirty dishes is the cause of the most common errors in urinalysis results.

It is also not recommended to collect urine during menstruation. But if you really need it, then a tampon and a thorough shower come to the rescue.

As with a blood test, you need to adjust your diet and stop taking medication. After some drugs or products (for example, beets, vitamins), the color of the urine changes (who will tell the laboratory assistant about this?), And alcohol is categorically contraindicated 24 hours before the analysis.

For general urinalysis use the first morning portion of urine (previous urination should be no later than 4-6 hours). Even if you forget to pee in a jar for the twentieth time when you wake up, you can’t fill it in the evening, otherwise the results will surprise not only you, but also the doctors.

If the patient, when passing the test, did everything that depended on him, then it’s up to the laboratory. And we must not forget that the result of the analysis is not a diagnosis of , it can only be established by the attending physician, comparing the patient’s complaints with clinical data and test results.

In the medical center “Nadezhda” you can always take tests for a child and an adult and get the results in the shortest possible time.

LLC “ECO-MED-S M” – complex equipping of laboratories with modern equipment in medical and scientific institutions. |OOO “ECO-MED-S M”

The EXIAS e1 analyzer is designed for the quantitative determination of electrolytes (Na+, K+, Cl-, Ca2+), pH in whole blood, serum, plasma, dialysis solution and aqueous solutions, and hematocrit (Hct ) in whole blood.

The analyzer is maintenance-free and has exceptional performance. Combines high accuracy and ease of use.
User manipulations are reduced to one step – inserting the cartridge into the analyzer (all in one cartridge system).

Universal cartridge includes:

• sensors, solutions, waste collection and quality control (optional)
• all wearing parts such as tubes, sample injection unit, valves, etc.

With its robust and compact design, the EXIAS e|1 is well suited for both point-of-care and laboratory applications

Specifications

• Built-in printer, barcode reader (optional)
• Data exchange with the laboratory information system in accordance with the protocol LIS2-A2 (ASTM)
• Network connection via LAN connector (RJ45) or WiFi adapter (optional)

Downloads

• RZN 2022-16823 Analyzer e1

• DS as of 17.