A blood count is a measurement of the amounts and types of blood cells in the body. Blood cells are formed in the bone marrow.

The body has three main types of blood cells:

• Red blood cells help carry oxygen and nutrients to the other cells in the body.

• Platelets help clot blood whenever you have a bruise or cut.

• White blood cells help prevent and fight infection.
  
  
  

Chemotherapy and/or radiation therapy can cause bone marrow suppression. This means the bone marrow may produce a lower number of blood cells for a period of time. As the effects of treatment wear off, the bone marrow increases production again. Blood cell counts will be checked often during treatment.