Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder characterized by a low platelet count (thrombocytopenia) due to the immune system mistakenly attacking and destroying platelets. Platelets are blood cells that help with clotting, so a low count can lead to easy bruising and bleeding that may be difficult to stop.

The "idiopathic" part of the name means that the cause is unknown, though it's believed to involve an abnormal immune response. In some cases, ITP may develop after a viral infection or as a side effect of certain medications. It can also occur as a primary condition or secondary to other autoimmune disorders.

Symptoms of ITP can vary but may include easy bruising, nosebleeds, bleeding gums, prolonged bleeding from small cuts, and, in severe cases, internal bleeding.

Treatment for ITP depends on the severity of symptoms and may include medications to boost platelet production, suppress the immune system's attack on platelets, or increase platelet count quickly in emergencies. In some cases, procedures like splenectomy (removal of the spleen) may be considered.