Test guide
Hematocrit Test
A hematocrit test is a blood test that measures the amount (percent) of your blood that is made up of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. The other parts of your blood include white blood cells (to help fight infection and other diseases), platelets (to help make blood clots to stop bleeding ), and a liquid called plasma.
What it is for
A hematocrit (HCT) test is often part of a complete blood count (CBC). A CBC is a common blood test that measures the number and type of cells in your blood. It is used to check your general health. It may also be used to monitor or help diagnose blood disorders. These could include anemia , a condition in which you don't have enough red blood cells, and polycythemia (erythrocytosis), an uncommon disorder in which you have too many red blood cells and your blood becomes too thick. Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also known as
- HCT, packed cell volume, PCV, Crit
- H and H (Hemoglobin and Hematocrit)
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