URL of this page: //www.nlm.nih.gov/medlineplus/ency/presentations/100152.htm

Complete blood count - series

Procedure

Procedure

Overview

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

Preparation: The skin should be cleaned with alcohol or iodine before the test. The patient should be seated comfortably or reclining.

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.

Although the CBC test is very safe, any blood drawing has a slight risk of complication, including:

  • Oozing of blood from puncture site
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Multiple punctures to locate veins
  • Infection (a slight risk any time the skin is broken)

Update Date 3/19/2012