What Causes Thrombocytopenia?

Many factors can cause thrombocytopenia (a low platelet count). The condition can be inherited or acquired. "Inherited" means your parents pass the gene for the condition to you. "Acquired" means you aren't born with the condition, but you develop it. Sometimes the cause of thrombocytopenia isn't known.

In general, a low platelet count occurs because:

  • The body's bone marrow doesn't make enough platelets.
  • The bone marrow makes enough platelets, but the body destroys them or uses them up.
  • The spleen holds on to too many platelets.

A combination of the above factors also may cause a low platelet count.


Source: National Heart, Lung, and Blood Institute, National Institutes of Health.