Hematocrit Test

Hematocrit is a test that calculates the percentage of blood that is comprised of red blood cells (RBC) and assesses following

Dehydration
Polycythemia
Response to anemia treatment
Affectivity of blood transfusions
Anemia.

The hematocrit point out the proportion of cells and fluids in the blood and is a part of the whole blood count test.

No special preparation is required in conducting this test. Blood for hematocrit may be composed either

by finger prick or sticking a needle into a vein, called venipuncture. When performing a finger puncture, the first drop of blood should be wiped off, as it dilute the sample with tissue fluid. A sample taker collects the sample following cleaning and disinfecting the skin at the needle prick area.

Fluid volume in the blood involves hematocrit values. Hematocrit reduces in pregnancy, due to the extra fluid. The blood sample should not be collected from an arm of a patient receiving I.V. (Intra venous) fluid or during hemolysis. In addition, certain drugs like penicillin and chloramphenicol lowers the hematocrit, while sugar levels above 400 mg/dl are known to raise results.

Reduction in the size or quantity of red blood cells RBC decreases the space occupied hence resulting in an elevated hematocrit.

Blood is composed of red blood cells (RBC), white blood cells (WBCs), platelets and plasma. A reduction in the

number or size of red cells also reduces the amount of space they occupy, resulting in lower hematocrit. Dehydration ponders the blood that increases the hematocrit. Thalassemia minor is an exception in that it usually causes an increase in the number of red blood cells RBC but because they are small it results in a decreased hematocrit.

Normal values differ with age and sex being 42 to 60 % at birth time, 42 to 52 % in adult men, 33 to 40 % in 6 to 12 months and 35 to 47 % in adult women. Lower hematocrit point to iron (Fe) deficiency anemia or other deficiencies. Other conditions that leads to lower hematocrit comprises of mineral or vitamin deficiencies, liver cirrhosis, recent bleeding, and malignancies. The most widespread cause of augmented hematocrit is dehydration and sufficient fluid intake brings back the hematocrit to normal.

Though, it may reflect a state called polycythemia vera, a person has more than the normal number of red blood cells (RBC) due to bone marrow problem or as recompense for insufficient lung functioning. Living at high altitudes leads to raised hematocrit values, body’s retort to the reduced oxygen obtainable at these heights. Constantly high values require the guidance of a doctor.