Table of ContentsView AllTable of ContentsPurpose of TestHow Is the HCT Test Done?Interpreting ResultsCorrecting Abnormal HCT Levels
Table of ContentsView All
View All
Table of Contents
Purpose of Test
How Is the HCT Test Done?
Interpreting Results
Correcting Abnormal HCT Levels
Ahematocrit(HCT) test, also known as the packed-cell volume (PCT), measures how much of your blood consists ofred blood cells.
Red blood cells carry oxygen from your lungs throughout your body. A low HCT could be due toanemia, a vitamin or mineral deficiency, or blood loss. Having too many blood cells could be a sign ofdehydration, heart disease, orpolycythemia vera(PV).
Purpose of the HCT Test
Red blood cells, also callederythrocytes, are important for distributing oxygen from the lungs to the rest of the body. The percentage of your blood that consists of red blood cells also indicates the (viscosity) thickness of blood.
A high or low result on an HCT test can:
What Other Tests Are Done With HCT?
An HCT test is usually ordered as part of acomplete blood count (CBC). A CBC provides information on the three major types of blood cells:
Other tests may be performed at the same time as the HCT test or as a follow-up to help with a diagnosis. These may include:
As a basic blood test, the HCT doesn’t require fasting or special considerations. Blood is drawn from the inside of the elbow or the back of the hand. With infants and young children, it may involve a small puncture in the heel or fingertip to collect blood onto a test strip.
7 Tips to Make Getting Blood Drawn Painless
How Blood Is Tested
Once your blood is collected, it’s placed in a centrifuge or an automated hematology analyzer instrument.
The centrifuge separates the red blood cells from the plasma (non-cellular liquid), white blood cells, and platelets, giving a direct measure of the percentage of RBCs in the blood sample.
Automated instruments determine the hematocrit (a calculated value) using various methods. Different ways instruments measure/count cells include:
Whichever method is used, the hematocrit is calculated from the RBC cell count (RBC), mean cell volume (MCV), and the total sample volume (RBC x MCV/10 = Hct).
Age and gender affect hematocrit level, but general guidelines for normal levels in adults and young children are as follows:
Your healthcare provider will take these factors into account when interpreting the results.
If your hematocrit results are outside the normal range, your healthcare provider may have you come in for additional blood tests to help diagnose the cause.Your healthcare provider may want to repeat the HCT test after weeks, months, or at least annually to monitor your levels.
Causes of High HCT
An above-normal HCT means you have too many red blood cells (polycythemia). Symptoms of high HCT levels include:
Causes of Low HCT
A low hematocrit number means that your body doesn’t have enough red blood cells in your blood. This is also called anemia. Symptoms of anemia include:
Anemia may be due to the following health conditions:
Anemia can also be a side effect ofcancer treatments, such aschemotherapyandradiation.Hematocrit results enable healthcare providers to manage anemia if it develops.
What HCT Level Is Considered Anemic?For men, an HCT level of less than 41% is considered anemic. For women, that number is slightly lower at less than 36%.The number varies for children depending on their age.
What HCT Level Is Considered Anemic?
For men, an HCT level of less than 41% is considered anemic. For women, that number is slightly lower at less than 36%.The number varies for children depending on their age.
If your HCT levels are abnormal, your healthcare provider may order additional tests to identify and treat the underlying cause.
For example, if test results point to a bone marrow problem, abone marrow examinationmay be needed. A sample of bone marrow is taken, usually from the hip, to check for lymphoma and similar disorders.
In addition to treating the underlying cause, your healthcare provider may recommend diet or lifestyle changes, supplements, or medications.
How to Increase HCT
Some examples of iron-rich foods include:
Your healthcare provider may also suggest taking over-the-counteriron supplements. If iron deficiency anemia is severe, ablood transfusionmay be needed.
If anemia is the result of a bacterial infection, you may need to beginantibiotics.
How to Lower a High HCT
If you have a condition that causes overproduction of RBCs, your healthcare provider may suggest lifestyle changes such asquitting smokingor adopting aheart-healthy diet.
Sometimes dehydration can cause high hematocrit levels. In this case, drinking lots of fluids can bring your levels back to normal.
In the rare case of PV, a healthcare provider can provide medication that will help you manage the condition, but it cannot be cured.
Best Foods to Eat If You Have Anemia (And What to Avoid)
Summary
A hematocrit test gives your healthcare provider important information about your health. The test measures the volume of red blood cells compared to the total volume of your blood.
The HCT test can help to diagnose or monitor blood disorders, dehydration, nutrient deficiencies, blood-related cancers, and many other conditions.
If your test results are abnormal, other tests may be performed at the same time or afterward to help identify the cause of anemia (low hematocrit) or high red blood cell counts, so you can get the right treatment.
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.U.S. National Library of Medicine. MedlinePlus.Hematocrit test.Avecilla S, Marionneaux S, Leiva T, et al.Comparison of manual hematocrit determinations versus automated methods for hematopoietic progenitor cell apheresis products.Transfusion. 2016;56(2):528-32. doi: 10.1111%2Ftrf.13346Seattle Children’s Lab.Hematocrit.Mount Sinai.Hemoglobin.U.S. National Library of Medicine. MedlinePlus.Anemia.National Cancer Institute.Anemia: Cancer Treatment Side Effect.American Red Cross.What does hematocrit mean?American Red Cross.Iron Rich Foods.National Heart, Lung, and Blood Institute.Iron-deficiency anemia.National Heart, Lung, and Blood Institute.Polycythemia Vera.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.U.S. National Library of Medicine. MedlinePlus.Hematocrit test.Avecilla S, Marionneaux S, Leiva T, et al.Comparison of manual hematocrit determinations versus automated methods for hematopoietic progenitor cell apheresis products.Transfusion. 2016;56(2):528-32. doi: 10.1111%2Ftrf.13346Seattle Children’s Lab.Hematocrit.Mount Sinai.Hemoglobin.U.S. National Library of Medicine. MedlinePlus.Anemia.National Cancer Institute.Anemia: Cancer Treatment Side Effect.American Red Cross.What does hematocrit mean?American Red Cross.Iron Rich Foods.National Heart, Lung, and Blood Institute.Iron-deficiency anemia.National Heart, Lung, and Blood Institute.Polycythemia Vera.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
U.S. National Library of Medicine. MedlinePlus.Hematocrit test.Avecilla S, Marionneaux S, Leiva T, et al.Comparison of manual hematocrit determinations versus automated methods for hematopoietic progenitor cell apheresis products.Transfusion. 2016;56(2):528-32. doi: 10.1111%2Ftrf.13346Seattle Children’s Lab.Hematocrit.Mount Sinai.Hemoglobin.U.S. National Library of Medicine. MedlinePlus.Anemia.National Cancer Institute.Anemia: Cancer Treatment Side Effect.American Red Cross.What does hematocrit mean?American Red Cross.Iron Rich Foods.National Heart, Lung, and Blood Institute.Iron-deficiency anemia.National Heart, Lung, and Blood Institute.Polycythemia Vera.
U.S. National Library of Medicine. MedlinePlus.Hematocrit test.
Avecilla S, Marionneaux S, Leiva T, et al.Comparison of manual hematocrit determinations versus automated methods for hematopoietic progenitor cell apheresis products.Transfusion. 2016;56(2):528-32. doi: 10.1111%2Ftrf.13346
Seattle Children’s Lab.Hematocrit.
Mount Sinai.Hemoglobin.
U.S. National Library of Medicine. MedlinePlus.Anemia.
National Cancer Institute.Anemia: Cancer Treatment Side Effect.
American Red Cross.What does hematocrit mean?
American Red Cross.Iron Rich Foods.
National Heart, Lung, and Blood Institute.Iron-deficiency anemia.
National Heart, Lung, and Blood Institute.Polycythemia Vera.
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