Complete Blood Count (CBC) blood test

What does the Complete Blood Count (CBC) measure?

A CBC measures the number, size and make-up of red blood cells, white blood cells and platelets, along with indices like MCV, MCH and RDW that describe your red cells in more detail.

Why is the Complete Blood Count (CBC) ordered?

It is ordered as a general health check, to look into tiredness, infection, bruising or bleeding, and to follow many long-term conditions over time.

Tests in this panel

Each test links to its own page with named reference-range sources.

Sources: [ICMR-NIN] [WHO] [CLSI] [British Journal of Haematology] [ICMR] [ICSH]

• HemoglobinHemoglobin is the iron-rich protein inside your red blood cells. It picks up oxygen in your lungs and carries it around your body.
• RBCRBC stands for Red Blood Cell count — the number of red blood cells in one microlitre of your blood. These cells carry a protein called haemoglobin (Hb) that picks up oxygen in your lungs and delivers it around your body [WHO, 2011].
• WBCWBC stands for White Blood Cell count — the number of white blood cells in one microlitre of your blood. These cells are your body's defence system, and they find and destroy bacteria, viruses and other threats [British Journal of Haematology, 2017].
• Platelet CountThis measures how many platelets sit in a set volume of your sample. The number reflects the balance between how fast your bone marrow makes them and how fast they are used up.
• Hematocrit (PCV)This measures the fraction of your total sample volume taken up by red cells, once they are spun and packed down. That proportion tracks both red cell numbers and how watery your blood is.
• MCVMCV is worked out by dividing the packed red cell volume by the number of red cells. The result reflects whether iron, vitamins, or other factors are shaping how those cells form.
• MCHMCH is the total hemoglobin in your sample divided across each red cell. Hemoglobin is the protein that ferries oxygen, so this figure tracks how well each cell is loaded.
• MCHCMCHC compares the hemoglobin to the space available inside your red cells. It gauges how concentrated that oxygen-ferrying protein is, rather than the total amount per cell.
• RDWRDW puts a number on the spread of red cell sizes around their average. A wider spread means the cells were made under changing conditions over time.
• NeutrophilsNeutrophils are the most common type of white blood cell. They are your body's first line of defence against bacteria and fungi.
• LymphocytesLymphocytes are a type of white blood cell. They are central to your body's targeted defence, including making antibodies that remember germs.
• MonocytesThis counts one class of immune cell that circulates briefly, then settles into tissues. There they engulf debris and dead cells and signal to other immune cells.
• EosinophilsEosinophils are a type of white blood cell. They take part in allergic reactions and help defend against certain parasites.
• BasophilsThis counts the least common immune cell, which stores histamine and other signals inside tiny granules. Releasing them helps drive swelling and allergic responses.
• ESRESR measures how fast your red blood cells sink to the bottom of a tube in one hour. Faster settling can reflect certain proteins in your blood.
• MPVMPV reports the average volume of each platelet in your sample. Freshly released platelets tend to be larger, so the figure hints at how briskly your marrow is producing them.
• PDWPDW puts a number on how widely platelet sizes range around their average. An uneven spread reflects changes in how they are being formed and released.
• Absolute Neutrophil CountAbsolute Neutrophil Count is the real number of neutrophils in a small amount of your blood. It is worked out from your white cell count and neutrophil share.
• Absolute Lymphocyte CountAbsolute Lymphocyte Count is the real number of lymphocytes in a small amount of your blood. It is worked out from your white cell count and lymphocyte share.
• Reticulocyte CountReticulocyte Count is the share of brand-new, young red blood cells in your bloodstream. It shows how hard your bone marrow is working to make red cells.
• Nucleated RBCThis counts immature red cells that still carry a nucleus (a central control part). Cells normally shed it before entering the bloodstream, so seeing them signals unusual release from the marrow.

Frequently asked questions

What is included in the Complete Blood Count (CBC)?

A CBC measures the number, size and make-up of red blood cells, white blood cells and platelets, along with indices like MCV, MCH and RDW that describe your red cells in more detail. It typically reports 21 results: Hemoglobin, RBC, WBC, Platelet Count, Hematocrit (PCV), MCV, MCH, MCHC, and more.

Why is the Complete Blood Count (CBC) ordered?

It is ordered as a general health check, to look into tiredness, infection, bruising or bleeding, and to follow many long-term conditions over time.

How should the Complete Blood Count (CBC) be read as a whole?

No single value tells the full story — the results are read together, and each value is compared against the reference range printed on your own report, which can vary by lab, method and equipment.

Do the reference ranges in the Complete Blood Count (CBC) vary between labs?

Yes. Ranges depend on the laboratory's equipment and method, so the range printed on your own report is the one that applies to your result. Each test page names the standards body behind its range.