Hematocrit

Part of speech: noun

Definitions

1. The proportion of the volume of red blood cells to the total volume of blood in a sample, expressed as a percentage, used to assess the concentration of red cells in circulation
2. A measurement indicating the fraction of blood occupied by erythrocytes, typically represented as a percentage, important for evaluating oxygen-carrying capacity and diagnosing blood disorders
3. The ratio of red blood cell mass to overall blood volume, given as a percentage, serving as an indicator of anemia, dehydration, or polycythemia in medical examinations

Etymology: Swedish physiologist Magnus Blix coined "hematocrit" in 1891, and the name is a deliberately constructed one: it joins "hemato-", from the Greek "haima" meaning blood, to the Greek "kritēs", meaning judge or umpire. Read literally, the word describes an instrument that judges blood, which is a fitting name for a device that separates blood into its components and reports how much of it is red cells. The "crit" in the middle is the part that puzzles many readers. It comes from "krinein", the Greek verb to separate or decide, the same root behind "critic" and "crisis." Blix's coinage therefore carries the sense of separating the blood into layers, with the red cells settling out in a measurable column.

Synonyms: packed cell volume, pcv