In vascular spasm, the smooth muscle in the walls of the vessel contracts dramatically.

platelets clump together, become spiked and sticky, and bind to the exposed collagen and endothelial lining.

Those more sophisticated and more durable repairs are collectively called coagulation, the formation of a blood clot.

hemophilia A (factor VIII deficiency)

Essential mediators that trigger the mechanical pathway of the coagulation cascade upon encountering any damage to the blood vessels.

Thrombocytopenia occurs when your bone marrow doesn’t make enough platelets, which are blood cells that form blood clots to help stop bleeding.

Bone marrow doesn’t make enough platelets.

Conditions that use up the platelet supply or destroy the platelets

Spleen traps platelets so they can’t circulate through the bloodstream.

Patients with ITP develop autoantibodies against platelet membrane proteins, specifically glycoprotein (GP) IIb/IIIa complex, GP Ib/IIa, and GP VI.

Easy bruising

abnormal bleeding

cuts that keep bleeding

Childhood ITP is often benign and self-limited, whereas ITP in adults tends to be more chronic and difficult to treat.

Corticosteroids

Intravenous immunoglobulin (IVIG)

Platelet transfusion

hemolytic transfusion reactions

The spleen is responsible for removing these damaged platelets and therefore removal of the spleen can help to keep more platelets circulating in the body.

Decreases antibody-dependent phagocytosis of platelets

decreases complement-dependent cytotoxicity