CBC Test Explained: What Your Complete Blood Count Reveals and Normal Ranges

Quick answer: A Complete Blood Count (CBC) measures your red blood cells and haemoglobin (oxygen carrying), white blood cells with a differential count (infection and immunity), and platelets (clotting). It helps detect anaemia, infections, dengue-related platelet drops, inflammation, and some blood disorders. Typical adult haemoglobin is about 13–17 g/dL for men and 12–15 g/dL for women, total WBC about 4,000–11,000 /cumm, and platelets about 1.5–4.5 lakh /cumm — but always use your lab's range. No fasting is needed, and results at Aarvak are typically ready within 6 hours.

The CBC is the single most commonly prescribed blood test in India. Doctors order it for fever, fatigue, before surgery, during pregnancy, for dengue monitoring and as part of every health checkup. Yet most people only look at haemoglobin and skip the rest. Here's what the whole report tells you.

Red Blood Cell Values

Haemoglobin (Hb)

The oxygen-carrying protein in red cells. Low haemoglobin means anaemia.

• Men: about 13–17 g/dL
• Women: about 12–15 g/dL
• Pregnancy: anaemia if below 11 g/dL

RBC Count and Haematocrit (PCV)

The number of red cells and the proportion of blood made up of red cells. A rising haematocrit in dengue can signal plasma leakage and needs attention — see dengue platelet monitoring.

Red Cell Indices — MCV, MCH, MCHC, RDW

These describe the size and colour of your red cells and point to the cause of anaemia:

• Low MCV (small cells): iron deficiency or thalassaemia trait
• High MCV (large cells): vitamin B12 or folate deficiency, alcohol, thyroid or liver disease
• High RDW: red cells of varying sizes, common in iron deficiency

Read more on iron deficiency anaemia and B12 deficiency.

White Blood Cell Values

Total WBC Count

• High (leukocytosis): bacterial infection, inflammation, stress, steroids, and rarely blood disorders
• Low (leukopenia): viral infections such as dengue, some medicines, and some bone marrow conditions

Differential Count

The WBC is split into five types, each with a role:

• Neutrophils: fight bacteria — high in bacterial infections
• Lymphocytes: fight viruses — high in many viral infections
• Eosinophils: high in allergies, asthma and worm infections — see allergy testing
• Monocytes: raised in some chronic infections
• Basophils: rarely significant on their own

Platelets

Platelets help blood clot.

• Low platelets (thrombocytopenia): dengue and other viral fevers, some medicines, immune conditions, liver disease
• High platelets: iron deficiency, inflammation, after surgery, and rarely bone marrow disorders

In dengue, platelet counts typically fall between days 3 and 7 of fever. Your doctor decides how often to repeat the CBC.

ESR — Often Done With CBC

The Erythrocyte Sedimentation Rate is a general marker of inflammation. It's non-specific — raised in infections, autoimmune conditions, anaemia and pregnancy — and is interpreted alongside symptoms. See CRP vs ESR.

When Is a CBC Ordered?

• Fever, especially lasting more than two to three days
• Fatigue, weakness or breathlessness
• Easy bruising or bleeding
• Before surgery — see pre-operative tests
• During pregnancy
• Monitoring long-term conditions and certain medicines
• As part of annual health checkups

How to Prepare

• No fasting is required for a CBC alone
• Avoid heavy exercise just before the test
• Stay normally hydrated — dehydration can falsely raise haemoglobin and haematocrit
• Tell the lab about recent illness, blood transfusion or medicines

Common CBC Patterns

• Low Hb + low MCV + high RDW: suggests iron deficiency
• Low Hb + high MCV: suggests B12/folate deficiency, thyroid or liver issues
• Low WBC + low platelets + fever: common in dengue and other viral fevers
• High WBC with high neutrophils + fever: suggests a bacterial infection
• High eosinophils: allergy, asthma or parasites

These are clues, not diagnoses — your doctor interprets them with your history and examination.

Frequently Asked Questions

What does a CBC test detect?

A CBC can detect anaemia, infections, inflammation, low platelets (as in dengue), allergies, and some blood disorders. It is also used to monitor treatment and general health.

Is fasting needed for a CBC test?

No. A CBC does not require fasting. You may need to fast only if other tests like blood sugar or lipid profile are done at the same time.

What is a normal platelet count?

A normal platelet count is roughly 1.5 to 4.5 lakh per cubic millimetre (150,000–450,000/µL), depending on the lab.

How long does a CBC report take?

At Aarvak, CBC reports are typically available within about 6 hours of sample collection.

Can a CBC detect cancer?

A CBC can show abnormalities that prompt further tests for blood cancers, but it cannot diagnose cancer on its own.

Which Aarvak packages include CBC?

All three ADC Swasthya packages (₹1,000, ₹2,000 and ₹3,000) include a Complete Blood Count.

Book a CBC Test in Gurugram

Get a CBC at Aarvak's Sector 67 lab or with home sample collection. For a complete baseline, the ₹1,000 ADC Basic Swasthya Panel includes CBC, sugar, HbA1c, lipid profile and urine routine. See our haematology tests or call +91 92663 33711.

This article is for general information only. Please discuss your results with your doctor.