Type of Blood (Test)

Red Blood Cells

The red blood cells carry oxygen to the body's tissues and remove carbon dioxide and other wastes.

White blood cells

White blood cells protect the body against infection. Types of white blood cells include neutrophils, banded neutrophils, lymphocytes, monocytes, and eosinophils.

Each type of white blood cell plays a different role in protecting the body. The numbers of each type of white blood cells give important information about the immune system. Too many or too few of the different types of white blood cells can be a sign of an infection, an allergic or toxic reaction to medicines or chemicals, and many conditions, such as leukemia.

Platelet

A platelet is the smallest type of blood cell. Platelets are the body's first defense against bleeding, helping the blood to clot (coagulate) by collecting at the site of a wound and clumping together to help stop the flow of blood.

People with very low levels of platelets or who have bleeding disorders may need to have transfusions of platelets to prevent excessive bleeding.