ITP stands for idiopathic thrombocytopenic purpura. In people with ITP, all of the blood cells are normal except for the blood platelets.
Platelets are the tiny cells that seal minor cuts and wounds and form blood clots.
A person with too few platelets bruises easily and bleeds for a long time after being injured. When the platelet count is very low, the person with ITP might have nosebleeds that are hard to stop, or might have bleeding in the intestines. The cause of ITP is not known. People with ITP form antibodies that destroy their blood platelets. Normally, antibodies are a healthy response to bacteria or viruses.