D69: Purpura and other haemorrhagic conditions

D69.3: Idiopathic thrombocytopenic purpura

They are formed in the bone marrow. Platelets are important for blood clotting. You don’t have enough platelets in your blood. The exact reason for this is not known. Your immune system is probably attacking your own platelets. This has broken the platelets in the blood. The immature platelets in the bone marrow can also be attacked, resulting in not enough platelets being reproduced.

The illness can occur after contact with certain pathogens or be caused by drugs. The disease may only exist for a short time or for a long period of time.