Idiopathic thrombocytopenic purpura (ITP) is a bleeding condition in which the blood does not clot properly due to a low number of blood cell fragments called platelets. Platelets are small particles that are essential for blood clotting. A low number of platelets is referred to as thrombocytopenia.

Signs and symptoms of ITP vary in their severity. Associated symptoms and signs can include bleeding, bruising (purpura), tiny red hemorrhages on the skin (petechiae), nosebleeds, heavy menstrual periods, and collections of blood under the skin (hematomas). The signs of bleeding may appear without a known reason for the bleeding.

Causes of idiopathic thrombocytopenic purpura (ITP)

Though the term idiopathic means that the cause of a condition is unknown, medical professionals believe an autoimmune response causes most cases of ITP.