Not medically reviewed
Haematology
Red blood cell count (RBC)
Not medically reviewed · Content last updated · 1 min read ·
This is the date the draft was written, not a medical review date.
The red-cell count gives the number of erythrocytes per unit volume and is interpreted together with haemoglobin, MCV and RDW to classify anaemia and erythrocytosis.
Reference interval
| Conventional (x10^6/µL) | SI (x10^12/L) | |
|---|---|---|
| Men | 4.5–5.9 x10^6/µL | 4.5–5.9 x10^12/L |
| Women | 4.1–5.1 x10^6/µL | 4.1–5.1 x10^12/L |
Specimen: Whole blood (EDTA) · Conventional × 1 = SI
Causes of high values
Polycythaemia vera, secondary erythrocytosis, dehydration, and thalassaemia trait (high count with low MCV).
Causes of low values
Anaemias (nutritional, haemolytic, aplastic, chronic disease), haemorrhage, overhydration and pregnancy.
Pre-analytical and method notes
Reference intervals depend on sex, age, altitude and analyser. Cold agglutinins and marked hyperglycaemia or leucocytosis can distort automated counts; check the film when indices are discordant.
References
- Rifai N, Horvath AR, Wittwer CT. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Elsevier, 6th edition (2018) — Tier 3 (textbook)
- McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. Elsevier — Tier 3 (textbook)
References are listed only where the article cites them. See the sources page for the full policy. How sources are chosen and credited