haematocrit
C2Technical / Medical
Definition
Meaning
The proportion of a blood sample that is made up of red blood cells, expressed as a percentage.
Also refers to the medical test or the device (a centrifuge tube) used to measure this proportion.
Linguistics
Semantic Notes
A key diagnostic parameter in assessing conditions like anaemia or polycythaemia. Not typically used outside medical contexts.
Dialectal Variation
British vs American Usage
Differences
The British spelling is 'haematocrit'. The American spelling is 'hematocrit'. Pronunciation of the initial 'h' and the vowel in the first syllable differs.
Connotations
Identical technical connotations in both varieties.
Frequency
Slightly more common in the US variant spelling 'hematocrit' in global medical literature, but 'haematocrit' is standard in the UK.
Vocabulary
Collocations
Grammar
Valency Patterns
patient + has + a + haematocrit + of + [value][verb: measured/checked/determined] + the + haematocritVocabulary
Synonyms
Strong
Neutral
Weak
Usage
Context Usage
Academic
Used in medical and biological research papers, clinical studies, and textbooks.
Everyday
Almost never used in casual conversation. A patient might hear it in a doctor's explanation.
Technical
Core term in haematology, clinical pathology, anaesthesiology, and nursing for patient assessment.
Examples
By Part of Speech
adjective
British English
- The haematocrit reading was abnormal.
- We need a haematocrit centrifuge.
American English
- The hematocrit value was abnormal.
- We need a hematocrit tube.
Examples
By CEFR Level
- The doctor said my haematocrit is a bit low.
- They took blood for a haematocrit test.
- A low haematocrit can be indicative of iron-deficiency anaemia.
- The patient's haematocrit level was monitored throughout the hospital stay.
- The study correlated altitude with a significant increase in mean haematocrit values.
- Determination of the haematocrit is essential prior to major surgery to assess the patient's reserve.
Learning
Memory Aids
Mnemonic
Think: HAEma (blood) + TO + CRIT (critical value). 'Haema' to criticise the health of your blood.
Conceptual Metaphor
BLOOD IS A MIXTURE (with the 'crit' being the settled, measurable part).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Direct translation trap: 'гематокрит' is a direct borrowing and cognate, but the concept might be unfamiliar. It is not a 'critic' ('критик') of blood.
Common Mistakes
- Misspelling: 'hematocrit' in British English, 'haematocrit' in American English. Mispronunciation: /heɪ.mə-/ instead of /hiː.mə-/.
Practice
Quiz
What does a 'haematocrit' measure?
FAQ
Frequently Asked Questions
For adult males, it's typically 40-54%, and for adult females, 36-48%. These ranges can vary slightly between laboratories.
It helps diagnose blood disorders like anaemia (low value) or polycythaemia (high value), and assesses a patient's fitness for procedures involving potential blood loss.
Haemoglobin measures the oxygen-carrying protein concentration inside red cells, while haematocrit measures the volume percentage of the red cells themselves. They are closely related but different metrics.
It is expressed as a percentage (e.g., 45%), though the measurement is sometimes referred to as a 'count' colloquially.