Definition of hematocrit in US English:


(British haematocrit)


  • 1The ratio of the volume of red blood cells to the total volume of blood.

    • ‘Complete blood cell data showed a hematocrit of 31.9% and a mean corpuscular volume of 91.3 fL.’
    • ‘His hemoglobin was 13, his hematocrit was 37.5, and his red blood cell count was 3.79.’
    • ‘Her current white blood cell count, hemoglobin, hematocrit, and red blood cell indices are all normal.’
    • ‘The ratio of total body to venous hematocrit was calculated for all patients.’
    • ‘This fluid is then centrifuged to leave a solution of red blood cells with a haematocrit of 0.5-0.6.’
    1. 1.1 An instrument for measuring this, typically by centrifugation.
      • ‘Your hematocrit result has to be above a thirty-eight and I was just below that.’
      • ‘Healthy children without a history of snoring who presented to the pediatrics clinic for well child visits and who had blood drawn for routine measurement of hematocrit were also recruited as control subjects.’
      • ‘Because severe anemia, defined as a hematocrit less than 0.15, we determined intraoperative estimated blood loss and obtained serial measurements of hematocrit.’
      • ‘Last spring they warned about abnormal test scores that recorded high readings of hematocrit, a measure of the volume of red blood cells.’
      • ‘But because the haematocrit measure is not specific - it can only detect possible abuse - they do not use it.’


Late 19th century: from hemato- ‘of blood’ + Greek kritēs ‘judge’.