Key points
- A CBC (complete blood count, also called a CBC or haemogram) measures your red cells and haemoglobin, white cells and platelets from one small blood sample. No fasting is needed.
- Low haemoglobin (anaemia) is the most common abnormal finding in India. In NFHS-5, 57% of women aged 15 to 49 had anaemia.
- White cell counts rise with infections and inflammation, and fall with some viral infections and medicines. Platelets often drop in dengue and other viral fevers.
- Normal ranges differ between labs, and between men and women. A slightly abnormal value is common and often repeated before anything else is done.
If you have had a fever, a health check-up or a pre-surgery test in India, you have almost certainly had a CBC. This page explains each part of it. For general tips on ranges, flags and units, see how to read a blood test report.
What a CBC test means
A complete blood count looks at the three types of cells in your blood:
- Red blood cells, which carry oxygen using a protein called haemoglobin.
- White blood cells, which fight infection.
- Platelets, which help blood clot.
The sample is collected in a tube with a lavender or purple cap, which contains an anticoagulant (EDTA) to stop it clotting. An automated analyser counts and measures the cells. You do not need to fast. Results are usually ready the same day.
CBC test normal range table
These are typical ranges for adults. Your lab's ranges may be a little different, and the range on your report is the one to use.
| Test on report | Typical adult range | What it tells you |
|---|---|---|
| Haemoglobin (Hb) | Men 13.0–17.0 g/dL; women 12.0–15.5 g/dL | Oxygen-carrying capacity; low means anaemia |
| Total RBC count | Men 4.5–5.5; women 3.8–4.8 million/µL | Number of red cells |
| Haematocrit (PCV) | Men 40–50%; women 36–46% | Share of blood made up of red cells |
| MCV | 80–100 fL | Average size of red cells |
| MCH | 27–32 pg | Haemoglobin per red cell |
| MCHC | 31.5–34.5 g/dL | Haemoglobin concentration in red cells |
| RDW | 11.5–14.5% | How much red cells vary in size |
| Total WBC count (TLC) | 4,000–11,000/µL | Infection, inflammation, bone marrow activity |
| Platelet count | 1.5–4.1 lakh/µL (150,000–410,000) | Clotting cells |
| MPV | About 7.5–11.5 fL | Average platelet size |
The tool on our home page shows where your own result sits within your lab's range.
Haemoglobin and red cells
The World Health Organization defines anaemia in adults as a haemoglobin below 13 g/dL in men, below 12 g/dL in non-pregnant women and below 11 g/dL in pregnancy. Anaemia is very common in India: in the National Family Health Survey 2019–21, 57% of women and 25% of men aged 15 to 49 had anaemia.
Low haemoglobin can cause tiredness, breathlessness on exertion, dizziness, headaches and pale skin. Common causes in India include iron deficiency (from diet, heavy periods, pregnancy or blood loss from the gut), vitamin B12 or folate deficiency, worm infections, chronic disease and inherited conditions such as thalassaemia trait.
High haemoglobin is less common. It can come from dehydration, smoking, living at high altitude, lung or heart disease, or rarely a bone marrow condition.
MCV, MCH and RDW: clues to the cause
These numbers describe the red cells themselves, and help your doctor work out why haemoglobin is low:
- Low MCV (small cells, microcytic): most often iron deficiency or thalassaemia trait. Both are common in India, and they are treated very differently, so iron should not be started without knowing which one it is.
- High MCV (large cells, macrocytic): often vitamin B12 or folate deficiency, alcohol, liver disease, thyroid problems or some medicines.
- High RDW: red cells vary a lot in size, which is typical of iron deficiency or a mix of causes.
Your doctor may order iron studies (ferritin), vitamin B12, or haemoglobin electrophoresis (HPLC) for thalassaemia, depending on the pattern.
White blood cells (WBC)
The total WBC count, also called the TLC (total leucocyte count), is typically 4,000 to 11,000 cells per microlitre in adults.
- High WBC (leucocytosis): most often a bacterial infection, inflammation, stress, smoking, pregnancy or steroid medicines. Very high counts, or abnormal cells on the smear, need prompt review.
- Low WBC (leucopenia): viral infections (including dengue), some medicines, vitamin B12 or folate deficiency, autoimmune conditions, or less often a bone marrow problem.
The differential count (DLC)
The differential shows the share of each type of white cell. Many labs also give absolute counts, which are more useful than percentages.
| Cell type | Typical share | Often raised by |
|---|---|---|
| Neutrophils | 40–75% | Bacterial infections, inflammation, stress, steroids |
| Lymphocytes | 20–40% | Viral infections, some chronic infections |
| Monocytes | 2–10% | Recovery from infection, chronic inflammation |
| Eosinophils | 1–6% | Allergies, asthma, worm infections |
| Basophils | 0–2% | Rarely significant on their own |
Platelet count
A typical platelet count is 1.5 to 4.1 lakh per microlitre (150,000 to 410,000/µL).
- Low platelets (thrombocytopenia) are common during dengue, malaria and other viral fevers, and usually recover as the illness settles. Other causes include some medicines, liver disease, autoimmune conditions and B12 deficiency. Sometimes the count is falsely low because platelets clumped in the tube; a repeat sample or a smear clears this up.
- High platelets (thrombocytosis) usually follow an infection, inflammation, iron deficiency or surgery, and settle on their own. Persistently very high counts need review.
In dengue, the WHO guidance stresses that warning signs, such as severe tummy pain, persistent vomiting, bleeding, restlessness or a falling platelet count with a rising haematocrit, matter more than any single platelet number. Platelet transfusions are not routinely needed.
Peripheral smear
If the machine flags something unusual, a trained person looks at a drop of your blood under a microscope. This peripheral smear can show the shape of red cells, immature white cells, malaria parasites or platelet clumps. Comments from the smear are usually printed at the bottom of the CBC report.
When to see a doctor quickly
- Bleeding gums, nosebleeds, blood in urine or stools, black stools, or new red or purple spots on the skin, especially with fever.
- Fever with a low WBC count, or if you are on chemotherapy.
- Breathlessness at rest, chest pain or fainting with low haemoglobin.
- In dengue: severe tummy pain, repeated vomiting, drowsiness or restlessness. Go to hospital, or call 112.
Questions to ask your doctor
- Which parts of my CBC are abnormal, and by how much?
- Do I need tests for iron, vitamin B12 or thalassaemia before any treatment?
- Should the CBC be repeated, and when?
- Could any medicine I take affect my counts?
Frequently asked questions
What does a CBC test show?
A complete blood count shows your haemoglobin and red cells, white blood cells and platelets. It helps detect anaemia, infections, inflammation and some blood disorders.
What is the normal range for a CBC test?
Typical adult ranges are haemoglobin 13–17 g/dL in men and 12–15.5 g/dL in women, WBC 4,000–11,000/µL and platelets 1.5–4.1 lakh/µL. Ranges vary between labs, so use the range printed on your report.
What is the normal platelet count?
A typical platelet count is 150,000 to 410,000 per microlitre, often written as 1.5 to 4.1 lakh. Platelets often fall temporarily during dengue and other viral fevers.
Do I need to fast for a CBC test?
No. A CBC does not need fasting, though you may be asked to fast if other tests such as blood sugar are done on the same sample.
What does a high WBC count mean?
A high white cell count most often means an infection or inflammation. Stress, smoking, pregnancy and steroid medicines can also raise it. Very high counts or abnormal cells need prompt review by a doctor.
Sources
- Tefferi A, Hanson CA, Inwards DJ. How to interpret and pursue an abnormal complete blood cell count in adults. Mayo Clin Proc 2005;80(7):923–936.
- World Health Organization. Guideline on haemoglobin cutoffs to define anaemia in individuals and populations. Geneva: WHO; 2024.
- International Institute for Population Sciences (IIPS) and ICF. National Family Health Survey (NFHS-5), 2019–21: India report. Mumbai: IIPS; 2021.
- World Health Organization. Dengue: guidelines for diagnosis, treatment, prevention and control. Geneva: WHO; 2009.
This article is general information for adults in India and is not a diagnosis or a treatment plan. Always discuss results and any changes with your own doctor. Read our editorial policy.