Hematocrit
Hematocrit is the share of the blood’s volume made up of red blood cells.
Hematocrit is the share of the blood’s volume that is made up of red blood cells, given as a percentage. Red blood cells carry oxygen from the lungs to the rest of the body. Hematocrit is read together with haemoglobin and the red cell count. Retesting shows how it changes over time.
Hydration has a large effect: little fluid raises hematocrit and a lot of fluid lowers it. Time at high altitude, smoking and endurance training also shift it, as do menstrual blood loss, blood donation and pregnancy. Intake of iron, vitamin B12 and folate matters for red blood cell production.
Foods that help
Iron from meat, fish, lentils and spinach, vitamin B12 from dairy, fish and eggs, folate from leafy greens and legumes, and enough fluid through the day.
Foods to limit
Tea and coffee with meals reduce iron absorption. Long periods of low fluid intake raise the value.
Track it through the year
One value is a snapshot. Following it up shows whether what you changed is working.
Related markers
Educational information only — not a diagnosis. Every result is checked against safe limits, and anything critical is escalated for follow-up.
See all 84 markers →