Deep vein thrombosis (etiology, symptoms and signs, diagnosis, treatment and prevention)

1. Big picture

Deep vein thrombosis (DVT) is clot formation in the deep venous system, most often in the lower limbs. It matters because it can cause pulmonary embolism (PE), post-thrombotic syndrome, and recurrent venous thromboembolism (VTE).

The exam pattern is:

Unilateral leg swelling + calf pain/tenderness + risk factor such as surgery, immobilization, cancer, pregnancy, estrogen therapy, previous DVT, thrombophilia → think DVT.

Always think in two directions:

Suspected DVT
   ↓
1. Is there already pulmonary embolism? dyspnea, chest pain, syncope, hemoptysis
2. What caused the clot? transient risk factor, cancer, pregnancy, thrombophilia, antiphospholipid