Deep Vein Thrombosis
Stasis, vessel wall injury and hypercoagulability tip the normal balance of coagulation towards clot formation in a deep vein, obstructing venous return and provoking local inflammation, and the real danger is that a fragment of that clot breaks off and embolises to the lungs.
First principles
Virchow's triad tips the balance towards clotting
Blood normally remains fluid because flow, an intact endothelium and a balance of pro- and anticoagulant factors keep coagulation in check. Any combination of stasis (immobility, long-haul travel, pregnancy, obesity), endothelial injury (surgery, trauma, cannulation) or hypercoagulability (malignancy, thrombophilia, oestrogen therapy, dehydration) shifts this balance towards clot formation, allowing a fibrin-platelet thrombus to form and propagate within a deep vein.
Educational content pending clinical review. Not medical advice.