Hematocrit is the percentage of the blood inside compressed red blood cell (RBCs). To compress these cells, you need to follow a process, which is termed as centrifugation. In this process, the ratio of the volume occupied by blood cells to the total volume of blood is determined. This ratio is shown as a percentage.

The normal hematocrit value is 38-52% for men and 37-47% for women. This means for a hematocrit count of 37%, there are 37 milliliters of RBCs in 100 milliliters of blood. Remember, the RBCs make up a quarter of the blood.

The hematocrit is generally recommended as a part of complete blood count along with some other tests, such as hemoglobin, white blood cell count, and platelet count. However, this test needs to be periodically repeated for various conditions, such as for the monitoring and treatment of anemia, polycythemia, dehydration, and bleeding.

The reduced hematocrit level in blood indicates anemia. However, further testing is required to determine the exact cause of the disease. Other than anemia, a low Hematocrit count may occur due to vitamin or mineral deficiencies, sudden bleeding, cirrhosis of the liver, and malignancies.

Hematocrit level in the body increases due to dehydration. However, with ample liquid intake, the hematocrit count can come down to normal. Also, the increased Hematocrit levels indicate polycythemia vera, where a person has higher than average number of RBCs. This situation occurs when the bone marrow manufactures more RBCs in order to carry adequate oxygen throughout the body.