1. Red blood cell values — the oxygen carriers
The top block of your CBC is about your red blood cells (RBCs). These are the cells that carry oxygen from your lungs to every tissue.
Haemoglobin (Hb) is the headline number. Normal is roughly 13–17 g/dL for men, 12–15 g/dL for women. Below that is anaemia. Above that is rare and usually means dehydration or a specific medical condition.
RBC count, PCV (packed cell volume), and MCV (mean corpuscular volume) all help refine the picture. Small red cells with low Hb suggest iron deficiency. Large red cells with low Hb suggest vitamin B12 or folate deficiency. Both patterns are extremely common in India and both are treatable.
2. White blood cell values — the immune system
The middle block covers your white cells (WBCs). Normal total WBC is 4,000–11,000 per µL.
But the more useful information is the differential — the percentages of each WBC type. Neutrophils go up during bacterial infections. Lymphocytes rise with viral infections (flu, COVID, dengue). Eosinophils spike with allergies or worm infestations. Monocytes creep up with chronic inflammation like TB.
A high total WBC with a neutrophil-dominant pattern is the classic 'you probably have a bacterial infection' signal. A high WBC with lymphocyte dominance is more likely viral. Your doctor uses this pattern to decide whether antibiotics are needed.
3. Platelet count — the clot-formers
Platelets stop bleeding. Normal count is 1.5–4.5 lakh per µL. Below 1 lakh is low; below 50,000 is a bleeding risk; below 20,000 usually needs hospitalisation.
The most common reason for a low platelet count in India is dengue fever. If you have a fever and your platelets are dropping day-over-day, tell your doctor immediately.
High platelets (above 4.5 lakh) are usually reactive — the body is inflamed or recovering from bleeding. Rarely, very high platelets suggest a bone-marrow condition.
4. What to do if a value is off
One abnormal value on a CBC rarely means disaster. Reports are snapshots — a slightly high WBC from a mild cold, mildly low Hb from a heavy period, low platelets from a viral fever — all resolve on their own.
What matters more is the pattern. Your doctor is trained to see the pattern; you don't have to. Your job is to bring the full report, mention any symptoms, and follow up if repeat testing was recommended.
- One value off, no symptoms → usually not urgent. Repeat as advised.
- Multiple values off in a consistent pattern → matters. Follow up.
- Any severely abnormal value → don't wait. Call your doctor.