What is a normal full blood count?

A full blood count is a test that measures the number of red cells, white cells and platelets in your blood.

  • Red cells carry oxygen around our bodies - haemoglobin is the part of the red cell that carries the oxygen
  • White cells help us fight infections, they include neutrophils and lymphocytes
  • Platelets help clot the blood, to stop us bleeding when we cut ourselves

Your doctor does a full blood count to

  • Check your general health
  • Diagnose certain conditions, such as anaemia or infections. It is also an early test for blood cancers such as leukaemia and lymphomas
  • Check the side effects of treatment - the number of cells in your blood can go down when you are having chemotherapy

There isn’t an exact range of normal for blood counts. The range of figures quoted as normal varies slightly and also differs between men and women.

Adult womanAdult man
Red blood cells3.8 to 5 x 10 12/l (3.8 to 5 million per cubic millimeter of blood)4.5 to 6.5 x 10 12/l (4.5 to 6.5 million per cubic millimeter of blood)
Haemoglobin (Hb)11.5 to 16.5 grams per 100ml of blood13 to 18 grams per 100ml of blood
White blood cells4 to 11 x 10 9/l (4,000 to 11,000 per cubic millimeter of blood)As for woman
Neutrophils2.0 to 7.5 x 10 9/l (2,000 to 7,500 per cubic millimeter of blood)As for woman
Lymphocytes1.3 to 4.0 x 10 9/l (1,300 to 4,000 per cubic millimeter of blood)As for woman
Platelets (thrombocytes)150 to 440 x 10 9/l (150,000 to 440,000 per cubic millimeter of blood)As for woman

Our figures are from the Oxford Handbook of Clinical Medicine and Anatomy and Physiology in Health and Illness (Ross and Wilson).

You can find out more about the different blood cells in our about cancer section on CancerHelp UK.