Deep Vein Thrombosis
Summary
Deep vein thrombosis (DVT) is clot formation in the deep veins, most commonly in the legs. It can be asymptomatic or present with leg pain, swelling, and warmth. Proximal DVT (above knee) carries higher risk of pulmonary embolism. Diagnosis uses Wells score to determine pre-test probability, followed by D-dimer or ultrasound. Treatment is anticoagulation with DOACs preferred.
Key Facts
- Definition: Thrombosis in deep venous system
- Incidence: 1-2 per 1,000 per year
- Pathognomonic: Unilateral leg swelling + risk factors
- Gold Standard Investigation: Compression ultrasound
- First-line Treatment: DOACs (rivaroxaban, apixaban)
- Prognosis: Good with treatment; PTS in 20-50%
Clinical Pearls
Wells Pearl: DVT unlikely (0-1) + negative D-dimer = DVT excluded.
Proximal Pearl: Proximal DVT needs treatment; calf DVT controversial.
DOAC Pearl: Rivaroxaban/apixaban don't need bridging with LMWH.
| Criteria | Points |
|---|---|
| Active cancer | 1 |
| Paralysis/recent immobilisation | 1 |
| Bedridden greater than 3d or surgery within 12 weeks | 1 |
| Tenderness along deep veins | 1 |
| Entire leg swollen | 1 |
| Calf swelling greater than 3cm vs other side | 1 |
| Pitting oedema | 1 |
| Collateral superficial veins | 1 |
| Previous DVT | 1 |
| Alternative diagnosis more likely | -2 |
Algorithm
Anticoagulation
| Drug | Regimen |
|---|---|
| Rivaroxaban | 15mg BD x21d then 20mg OD |
| Apixaban | 10mg BD x7d then 5mg BD |
| LMWH/Warfarin | Alternative |
Duration
| Type | Duration |
|---|---|
| Provoked | 3 months |
| Unprovoked | 6+ months or indefinite |
| Cancer | LMWH or DOAC long-term |
-
NICE guideline NG158. Venous thromboembolic diseases. 2020.
-
Kearon C et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline. Chest. 2016;149(2):315-352. PMID: 26867832
Viva Points
"DVT: Wells score for probability. Unlikely + negative D-dimer = excluded. USS if likely. DOACs first-line. Duration: provoked 3m, unprovoked longer."
Last Reviewed: 2026-01-01 | MedVellum Editorial Team