Hematocrit levels that are too high or too low can indicate a blood disorder, dehydration, or other medical conditions.

The hematocrit is slightly more accurate, as the PCV includes small amounts of blood plasma trapped between the red cells.

An estimated hematocrit as a percentage may be derived by tripling the hemoglobin concentration in g/dL and dropping the units.

[13] Through differential spectrophotometry, the differences in optical densities of a blood sample flowing through small-bore glass tubes at isosbestic wavelengths for deoxyhemoglobin and oxyhemoglobin and the product of the luminal diameter and hematocrit create a linear relationship that is used to measure hematocrit levels.

[15] Additionally, there have been cases in which the blood for testing was inadvertently drawn proximal to an intravenous line that was infusing packed red cells or fluids.

[citation needed] Hematocrit can vary from the determining factors of the number of red blood cells.

Thus, tests on hematocrit levels are often carried out in the process of diagnosis of such conditions,[3] and may be conducted prior to surgery.

In order to maintain pressure, the capillaries branch off to a web of vessels that carry blood into the venules.

In tube hematocrit, plasma fills most of the vessel while the red cells travel through in somewhat of a single file line.

[citation needed] Relationships between hematocrit, viscosity, and shear rate are important factors to put into consideration.

Additionally, a higher education in a parent has been put into account for a rise in mean hematocrit levels of the child.