Hematocrit (HCT)

Hematocrit is the volume percentage of red blood cells (erythrocytes) in a sample of whole blood, serving as a fundamental measurement of the blood's oxygen-carrying capacity. It is typically determined by centrifuging a blood sample to separate the cellular components from the plasma, a process also known as the packed cell volume (PCV) (StatPearls: https://www.ncbi.nlm.nih.gov/books/NBK542270/). While not a therapeutic target molecule itself, hematocrit is a critical clinical biomarker used to diagnose and monitor various hematologic and systemic conditions, including anemia, polycythemia, and dehydration (Mayo Clinic: https://www.mayoclinic.org/tests-procedures/hematocrit/about/pac-20384772). Low hematocrit levels often indicate reduced red blood cell production or increased loss, common in chronic kidney disease or nutritional deficiencies, while elevated levels are seen in primary or secondary polycythemia and severe dehydration (NIH: https://medlineplus.gov/lab-tests/hematocrit-test/). Pharmacological management often involves erythropoiesis-stimulating agents (ESAs) or iron supplementation to normalize these levels, though clinicians must carefully monitor hematocrit to avoid hyperviscosity and associated cardiovascular risks.

Other names

Packed cell volumePCVErythrocyte volume fractionEVF

Drugs do not target hematocrit directly as it is a measurement; instead, agents like erythropoiesis-stimulating agents (ESAs) bind to erythropoietin receptors on erythroid progenitor cells in the bone marrow to stimulate red blood cell production, thereby increasing the hematocrit percentage.