In 1856, Rudolf Virchow identified three conditions that cause blood clots to form. Nearly 170 years later, the framework is unchanged.
Click each factor to activate
0 / 3
Risk Level
No active factors
When none of Virchow's conditions are present, blood flows normally and clots form only where they should — at the site of injury, as a protective response.
Factor 01
Vessel Wall Injury
Damage to the endothelium — the inner lining of blood vessels — that triggers clotting.
High blood pressure
Smoking or diabetes
Atherosclerotic plaque
Surgical procedures
Factor 02
Slow Blood Flow
Stasis allows clotting factors to accumulate rather than being swept through the circulation.
Long-haul flights (PVG–LHR)
Prolonged desk work
Atrial fibrillation
Post-surgical bed rest
Factor 03
Hypercoagulability
Blood that is chemically primed to clot more readily than it should.
Genetic clotting disorders
Cancer or pregnancy
Hormonal contraception
Severe dehydration
For educational purposes only. This does not constitute medical advice. If concerned about thrombosis risk, consult a qualified physician.