Thrombocytopenia is a disorder in which there are too few platelets and the blood does not clot properly. People who have thrombocytopenia may bleed a lot from an injury because they have an abnormally low number of platelets.

Some conditions or diseases lead to thrombocytopenia because they destroy a person's platelets or interfere with their production. Certain medicines may also cause thrombocytopenia. A person who has a low platelet count with no known cause is said to have idiopathic thrombocytopenic purpura (ITP).

Symptoms of thrombocytopenia include:

• Easy or excessive bruising.
• Pinpoint-sized red spots (petechiae) around the feet and ankles. In more serious cases of thrombocytopenia, the spots are larger and more widespread (purpura).
• Nosebleeds.
• Heavy menstrual flow.

Treatment for low platelets starts with finding a cause that can be eliminated, such as changing a drug the person is taking or treating an infection. Treatment may include platelet injections into a vein, called platelet transfusion; taking medicines to stop destruction of the platelets; taking medicine that helps the body make more platelets; or surgery to remove the spleen.