Thrombocytopenia is the medical term for a low blood platelet count. Platelets (thrombocytes) are colorless blood cells that play an important role in blood clotting. Platelets stop blood loss by clumping and forming plugs in blood vessel holes.
Thrombocytopenia often occurs as a result of a separate disorder, such as leukemia or an immune system problem, or as a medication side effect. Thrombocytopenia may be mild and cause few signs or symptoms. In rare cases, the number of platelets may be so low that dangerous internal bleeding can occur.
Thrombocytopenia usually improves when the underlying cause is treated. Sometimes medications, surgery or a blood transfusion can help treat chronic thrombocytopenia.