Platelet activation

Platelet activation is a "series of progressive, overlapping events, triggered by exposure of the platelets to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug."

Platelet activation, along with coagulation, leads to hemostasis.

Platelet activation is inhibited for medical purposes by drugs called platelet aggregation inhibitors.