Question

What's virchow’s triad?

Answer 1

Over a century ago, diagnosticians described 3 factors that are critically important within the event of venous thrombosis: (1) venous stasis, (2) activation of curdling, and (3) vein damage. These factors have come to be called the Virchow triad.

Complete answer:
Virchow’s triad describes three factors that contribute to the event of venous thrombosis: hypercoagulability, stasis and endothelial injury. Yet, extensive review of the historical literature casts doubt on the existence of a triad described by Virchow within the shape it's currently quoted throughout contemporary medical literature.
Certainly his work involved extensive study of thrombosis and embolism, with these two terms being coined by Virchow, but a triad of things regarding the event of phlebothrombosis is elusive. Interestingly, Virchow only began to be routinely credited with this triad 100 years after publication of his work on phlebothrombosis.
This acknowledgement coincided with the buildup of experimental evidence for the role these factors play in thrombogenesis. Controversial because the origins of Virchow’s triad could also be, it's apt given his substantial contribution to our knowledge of venous thromboembolism, and also the indisputable fact that the triad continues to be clinically relevant today that a triad per Virchow should remain.

Note:
Although the concept of the triad is often attributed to Virchow, he didn't include endothelial injury in his description. This has been attributed to a dispute Virchow had with Jean Cruveilhier, who considered local trauma of primary importance within the event of blood vessel thrombosis.