Definition of hematocrit
: the ratio of the volume of red blood cells to the total volume of blood as determined by separation of red blood cells from the plasma usually by centrifugation
Did You Know?
Our blood is mostly made up of four components: plasma, red blood cells, white blood cells, and colorless blood cells called platelets. An instrument called a hematocrit (because it "judges" the blood) is used to separate a sample of blood into its components. The normal hematocrit for men is about 48%, for women about 38%. An abnormal proportion of red blood cells, either too many or too few, is a good early indicator of many diseases. So when you give blood as part of a physical exam, your hematocrit is one of the findings your doctor will often check.
Origin and Etymology of hematocrit
International Scientific Vocabulary hemat- + Greek kritēs judge, from krinein to judge — more at certain
First Known Use: circa 1903
Medical Definition of hematocrit
1: an instrument for determining usually by centrifugation the relative amounts of plasma and corpuscles in blood
2: the percent of the volume of whole blood that is composed of red blood cells as determined by separation of red blood cells from the plasma usually by centrifugation <a hematocrit ranging from 42% to 52% in males and 35% to 47% in females is typically considered normal>—called also packed cell volume
Learn More about hematocrit
Britannica.com: Encyclopedia article about hematocrit
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