What is a hematocrit?

Hematocrit (Hct) is a medical test that measures the volume percentage of red blood cells (RBCs) in the blood. Packed cell volume (PCV) is an older name for hematocrit.

Along with the red blood cell count (RBC) and hemoglobin, hematocrit is part of a complete blood count (CBC), a group of tests that evaluate the cells in the blood. A CBC can help diagnose various medical conditions, such as anemia and dehydration. For example, a high hematocrit may indicate dehydration or a blood disorder such as polycythemia vera, while a low hematocrit may indicate anemia.

Results of the hematocrit test are usually given as a percentage. The normal range for hematocrit is about 36-48% for women and 41-50% for men.