What this marker measures
Hematocrit generally mirrors hemoglobin trends. As a rough rule, hematocrit (%) is approximately three times the hemoglobin value (g/dL), though this varies.
High or low: what it can mean
High Hematocrit
A high hematocrit means a larger fraction of the blood is red blood cells than normal. This can occur with dehydration or conditions causing excess red cell production.
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Low Hematocrit
A low hematocrit suggests a smaller proportion of red blood cells, often seen alongside low hemoglobin as part of anemia.
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Frequently asked questions
What is Hematocrit?
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Hematocrit measures the proportion of blood volume made up by red blood cells, expressed as a percentage.
What does Hematocrit measure?
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Hematocrit generally mirrors hemoglobin trends. As a rough rule, hematocrit (%) is approximately three times the hemoglobin value (g/dL), though this varies.
What does high Hematocrit mean?
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A high hematocrit means a larger fraction of the blood is red blood cells than normal. This can occur with dehydration or conditions causing excess red cell production.
What does low Hematocrit mean?
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A low hematocrit suggests a smaller proportion of red blood cells, often seen alongside low hemoglobin as part of anemia.
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
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Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.