Idiopathic Thrombocytopenic Purpura (ITP) | Causes & Risk Factors


What causes ITP?

The cause of ITP is not known. People who have ITP form antibodies that destroy their blood platelets. Normally, antibodies are a healthy response to bacteria or viruses. In people who have ITP, however, the antibodies attack the body's own blood platelets.

Who gets ITP?

There are 2 types of ITP. One type affects children, and the other type affects adults. In children, the usual age for getting ITP is 2 to 4 years of age. Most adults with ITP are young women, but it can occur in anyone. ITP does not seem to be hereditary (run in families). ITP is not contagious (you can’t “catch it” from someone else).

Written by editorial staff

Reviewed/Updated: 03/14
Created: 09/00