Montrose Q: What causes clots?
Platelets, the tiniest cells in the blood, adhere to sticky or cut surfaces and become activated, exposing molecules on their surface that interact with the cascade of clotting proteins which are abundant in blood. The proteins are changed from an inactive to an active state, eventually resulting in the conversion of soluble fibrinogen to insoluble polymeric fibrin, the essential backbone of a clot. Rough surfaces can cause clotting (possibly the surfaces of atherosclerotic blood vessels), as can slowed flow in veins (deep vein thrombosis as sometimes seen in travelers sitting for extended periods), and turbulent flow (for example around damaged heart valves).
