A sticky problem solved
A small cut won’t bleed for long because tiny blood cells called platelets stick together and trigger clots. Damaged blood vessels and red blood cells release a compound known as adenosine diphosphate, or ADP, which triggers the process that makes platelets sticky.
Sometimes, however, overly reactive platelets are attracted to arteries damaged by fatty buildup. There, they form clots that, if dislodged, can sweep into the heart or brain, where they sometimes cause heart attacks or strokes.