Complete blood count - series

A CBC requires a simple blood drawing. Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand.

Preparation: There is no special preparation needed for this test.

How the test will feel:

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. After the blood is drawn, there may be some throbbing.

There are a few slight risks associated with a CBC:

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)
• Multiple punctures to locate veins

Review Date: 08/03/2004
Reviewed By: Marcia S. Brose, M.D., Ph.D., Assistant Professor, Hematology/Oncology, The University of Pennsylvania Cancer Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.