CBC Blood Test Explained: What Each Value Means

By Dashvanth Healthcare Medical Team · Reviewed by our specialists · East Delhi

What Is a CBC?

A Complete Blood Count (CBC) is the most commonly ordered blood test, providing a comprehensive snapshot of your blood's cellular components. It is used to diagnose anaemia, infections, inflammatory conditions, blood cancers, and monitor treatment response.

Key Values Explained

Red Blood Cells (RBC)

• Normal: Men 4.5–5.9 million/μL; Women 4.0–5.2 million/μL
• Low (anaemia): fatigue, pallor, breathlessness
• High (polycythaemia): increased clot risk

Haemoglobin (Hb)

• Normal: Men 13–17 g/dL; Women 12–15 g/dL; Children varies by age
• Low = anaemia (iron deficiency most common; also B12, thalassaemia)
• Hb below 8 g/dL is severe anaemia

MCV (Mean Corpuscular Volume)

• Small (microcytic, MCV <80): iron deficiency or thalassaemia
• Large (macrocytic, MCV >100): B12 or folate deficiency, liver disease, medications

White Blood Cells (WBC) — 4,000–11,000/μL

• High (leukocytosis): infection, inflammation, stress, steroids, rarely leukaemia
• Low (leukopenia): viral infections, medications, immune disorders
• Differential (neutrophils, lymphocytes, eosinophils, etc.) tells you the TYPE of problem

Neutrophils (Normal 40–75%)

• High (neutrophilia): bacterial infection, steroids
• Low (neutropenia): risk of serious infection below 0.5 × 10⁹/L

Eosinophils (Normal 1–6%)

• High (eosinophilia): allergies, asthma, parasitic infections

Platelets — 150,000–400,000/μL

• Low (thrombocytopenia): dengue, ITP, bone marrow problem, medications
• High (thrombocytosis): reactive (infection, iron deficiency) or rarely bone marrow disorder