Red blood cell parameters
| Parameter | Normal range | What it measures |
|---|
| Haemoglobin (Hb) | Men: 13.5–17.5 g/dL; Women: 12.0–15.5 g/dL | Oxygen-carrying protein — low = anaemia |
| Haematocrit (HCT/PCV) | Men: 41–53%; Women: 36–46% | Percentage of blood that is red cells |
| RBC count | Men: 4.5–5.9 M/µL; Women: 4.0–5.2 M/µL | Number of red blood cells |
| MCV (mean corpuscular volume) | 80–100 fL | Size of red cells: low = iron def; high = B12/folate def |
| MCH (mean corpuscular haemoglobin) | 27–33 pg | Haemoglobin per cell — parallels MCV |
| MCHC | 32–36 g/dL | Haemoglobin concentration in cells |
| RDW (red cell distribution width) | 11.5–14.5% | Variation in red cell size — raised in iron def & B12 def |
White blood cell parameters
| Parameter | Normal range | Clinical meaning when abnormal |
|---|
| WBC (total white count) | 4,500–11,000/µL | High = infection/inflammation; low = viral infection, drugs, bone marrow problem |
| Neutrophils (ANC) | 1,800–7,700/µL (40–70%) | Bacterial infection fighter — low (neutropenia) = severe infection risk |
| Lymphocytes | 1,000–4,800/µL (20–40%) | Viral immunity — high in viral infections; low in HIV, steroids |
| Monocytes | 200–800/µL (2–8%) | Chronic infection, TB, monocytic leukaemia |
| Eosinophils | 100–500/µL (1–4%) | Allergy, asthma, parasites — raised in eosinophilic conditions |
| Basophils | 0–100/µL (<1%) | Allergic reactions, chronic myeloid leukaemia |
Platelet parameters
| Parameter | Normal range | Clinical meaning |
|---|
| Platelet count | 150,000–400,000/µL | Low (<150k) = thrombocytopenia — bleeding risk; High (>400k) = thrombocytosis — clot risk |
| MPV (mean platelet volume) | 7.5–12.5 fL | Platelet size — large MPV with low count suggests ITP or platelet destruction |
How to interpret anaemia on a CBC
The MCV is the key to classifying anaemia: Low MCV (microcytic): iron deficiency (most common), thalassaemia, anaemia of chronic disease. Normal MCV (normocytic): acute blood loss, anaemia of chronic disease, kidney disease, mixed deficiency. High MCV (macrocytic): vitamin B12 deficiency, folate deficiency, alcohol, hypothyroidism, certain medications (hydroxyurea, methotrexate).
Questions to ask your doctor
- Which parameters are outside the normal range?
- Is my anaemia microcytic, normocytic, or macrocytic?
- Is my white count high — suggesting active infection?
- Are my platelets low enough to cause bleeding risk?
Medical Disclaimer: For educational purposes only. Always consult a qualified healthcare professional for diagnosis and treatment.