A CBC measures the different cells in your blood — red cells, white cells and platelets. It is one of the most commonly ordered blood tests.
Why this test is done
- Check for anaemia through haemoglobin and red cell measurements
- Look for signs of infection through the white blood cell count
- Check platelets, which help blood to clot — important in dengue
- Monitor known conditions and the effects of some treatments
How to prepare
- No fasting is needed for a CBC alone
- If it is combined with a blood sugar or lipid test, follow the fasting instructions for those
- Tell the laboratory about any medicines you take
Understanding your results
- Haemoglobin below the normal range suggests anaemia, and the red cell size helps point to the cause
- A raised white cell count often suggests infection or inflammation; a low count has several possible causes
- A low platelet count is watched closely in dengue, but it is interpreted together with symptoms and other results, not on its own
- Ranges differ slightly between laboratories, so always read your result against the range printed on your own report
Read your report with your doctor
Reference ranges differ between laboratories, and a value slightly outside the range is often normal for you. What matters is the pattern across your results, your symptoms and your history — which is why the report belongs in a consultation, not a search box.
Frequently Asked Questions
Do I need to fast for a CBC test?
No. A complete blood count does not require fasting. You only need to fast if it is being done together with tests that require it, such as fasting blood sugar or a lipid profile.
Can a CBC show anaemia?
Yes. Haemoglobin below the normal range on a CBC is what usually first suggests anaemia, and the red cell measurements help point towards the cause. Confirming the cause often needs further tests.
What does a low platelet count mean in dengue?
Platelets commonly fall in dengue, which is why the count is followed daily. The number is interpreted together with your symptoms and other results, not on its own — a falling count in someone who is well is managed differently from one in someone with warning signs.
What this costs, and what is free
Routine blood tests are generally free at government hospitals and health and wellness centres when ordered there.
Private lab prices for the same test vary widely between cities and between labs in the same city. It is worth asking the price before agreeing, and worth asking your doctor which tests are genuinely needed rather than accepting a bundled package.
Source: Ayushman Bharat PM-JAY, National Health Authority
Prices and scheme rules change. Confirm current details with the hospital or Kendra before you rely on them.