Wells Score for DVT

Wells score for DVT: clinical probability of deep vein thrombosis

The Wells score for DVT gives you a clinical probability of deep vein thrombosis in the lower limbs. Each item adds a point: active cancer (1), paralysis/recent plaster immobilization (1), bed rest >3 days or major surgery within 4 weeks (1), tenderness along the deep venous system (1), entire leg swollen (1), calf swelling >3 cm vs the other side (1), pitting edema (1), collateral superficial veins (1). When an alternative diagnosis is at least as likely as DVT, you subtract points (−2). How to read the total: 0 low, 1–2 moderate, ≥3 high probability. Example: a patient with tenderness along the deep venous system (1) plus pitting edema (1) lands on 2 points, so moderate probability — order a D-dimer and a venous duplex if it comes back positive.

Clinical context

Emergency departments and primary care use it to stratify suspected DVT, and it really earns its keep paired with the D-dimer. A low Wells with a negative D-dimer rules out DVT, with a negative predictive value above 99%; anything intermediate or high goes straight to compression duplex ultrasound. That saves unnecessary tests and gets people out the door faster. Watch the limits, though: it's less reliable in inpatients, in pregnancy, and in recurrent DVT, where modified Wells or Hamilton fit better. Read it alongside the history (HRT, long-distance travel, thrombophilia) and the physical exam, never in isolation.

FAQ

Does Wells confirm DVT? No. It gives you a probability and nothing more. To confirm the diagnosis you still need a duplex ultrasound or venography.

Can I use Wells in pregnancy? Its standard performance drops during pregnancy. The LEFt rule (Left leg, Edema, First trimester) fits better there, while venous duplex stays the first-line test.

What is the difference from Wells for PE? They're two separate scores. Wells for DVT looks at the lower limb, while Wells for PE assesses suspected pulmonary embolism using its own criteria (hemoptysis, tachycardia, HR >100, and so on).

And the −2 for alternative diagnosis? When cellulitis, a ruptured Baker cyst, or a muscle hematoma looks just as likely or more so, you take off 2 points. That subtraction is where clinical judgment does the heavy lifting.