Hematocrit
Hematocrit is the percentage of blood volume occupied by red blood cells. It is either directly measured by centrifuging blood or calculated from RBC count and MCV. Hematocrit is approximately 3 times the hemoglobin value (in g/dL) and provides similar clinical information about oxygen-carrying capacity.
Why it matters: Low hematocrit is associated with anemia and tracks with symptom severity. High hematocrit raises blood thickness and is associated with greater clotting risk. Because it reflects both red-cell mass and plasma volume, it is sensitive to hydration status.
May increase with:
May decrease with:
What is Hematocrit?
Hematocrit is the percentage of blood volume occupied by red blood cells. It is either directly measured by centrifuging blood or calculated from RBC count and MCV. Hematocrit is approximately 3 times the hemoglobin value (in g/dL) and provides similar clinical information about oxygen-carrying capacity.
What might a high or low Hematocrit mean?
Low hematocrit is associated with anemia and tracks with symptom severity. High hematocrit raises blood thickness and is associated with greater clotting risk. Because it reflects both red-cell mass and plasma volume, it is sensitive to hydration status.
What is the typical reference range for Hematocrit?
The general-population reference range shown here is 39 – 50 %. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect Hematocrit?
It may be higher with: Dehydration (concentrated blood), Smoking, High altitude, Testosterone therapy, Polycythemia vera, Chronic hypoxia (lung disease, sleep apnea), Diuretics. It may be lower with: Anemia (any cause), Overhydration (IV fluids), Blood loss, Chronic kidney disease, Pregnancy (physiological hemodilution), Bone marrow failure.
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