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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Deep vein thrombosis

Cardiology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Escalate

DVT symptoms plus new breathlessness, chest pain, haemoptysis, syncope or haemodynamic compromise may indicate pulmonary embolism: activate the PE/emergency pathway rather than completing an isolated DVT work-up.

Synopsis

Apply the NICE two-level Wells pathway, avoid unsafe diagnostic delay and choose initial anticoagulation with UK-specific modifiers.

  • Use the 2-level DVT Wells score: 2 points or more means DVT likely; 1 point or less means DVT unlikely.
  • Likely DVT: obtain proximal leg-vein ultrasound within 4 hours if possible; if delayed, give interim therapeutic anticoagulation and scan within 24 hours.
  • Unlikely DVT: obtain D-dimer within 4 hours; if delayed, give interim therapeutic anticoagulation while awaiting the result.
  • A positive D-dimer is not diagnostic; it triggers ultrasound. Consider an age-adjusted threshold for people over 50.
  • If initial proximal ultrasound is negative but D-dimer positive, repeat proximal ultrasound in 6–8 days.
  • Confirmed proximal DVT usually needs at least 3 months of anticoagulation; review provoked versus unprovoked risk, bleeding and recurrence at 3 months.
  • NICE generally offers apixaban or rivaroxaban first, but active cancer, triple-positive antiphospholipid syndrome, pregnancy, extremes of weight and renal/hepatic impairment alter choice.
  • Do not order thrombophilia testing while continuing anticoagulation or after a clearly provoked event unless a specific NICE indication will change management.

Key red flags

Phlegmasia

Massive painful swelling, cyanosis, sensory/motor change or threatened perfusion from extensive venous occlusion requires emergency vascular/haematology assessment.

Pulmonary embolism clues

Dyspnoea, pleuritic pain, tachycardia, haemoptysis, syncope, hypoxia or shock require immediate PE assessment.

Investigation priorities

01
Two-level DVT Wells scoreFirst step

Set the NICE diagnostic pathway before testing.

Management branches

likelyWells score at least 2

Clinically suspected DVT with a likely 2-level Wells score.

  1. First: proximal leg-vein ultrasound with result within 4 hours if possible.
  2. Next: if ultrasound cannot be obtained within 4 hours, take D-dimer, give interim therapeutic anticoagulation and obtain ultrasound within 24 hours.
  3. Next: if scan is positive, continue treatment; if negative, use D-dimer to decide discharge versus repeat scan.
  4. Escalation: after a negative scan with a positive D-dimer, stop interim therapeutic anticoagulation unless it is treating another indication, and repeat proximal ultrasound in 6–8 days; give clear PE and deterioration safety-netting.
special groupsChoice modifiers

A condition that makes routine DOAC treatment uncertain or unsuitable.

  1. First: pregnancy/breastfeeding—use an obstetric/haematology LMWH pathway, not a DOAC.
  2. Next: established triple-positive APS—offer LMWH or UFH concurrently with a vitamin K antagonist for at least 5 days or until INR is at least 2.0 in 2 consecutive readings, then continue VKA alone.
  3. Next: renal/hepatic impairment, active cancer or weight below 50 kg/above 120 kg—select and monitor therapy with specialist/product guidance.
  4. Escalation: major bleeding, recurrent VTE or suspected HIT needs immediate anticoagulation review and specialist management.

Key medicines

Apixaban10 mg orally twice daily for 7 days, then 5 mg twice daily; if extended prevention is chosen after 6 months, 2.5 mg twice daily.Check renal/hepatic function, interactions and bleeding; use caution with creatinine clearance 15–29 mL/min. Contraindicated in active significant bleeding and not used for pregnancy/breastfeeding.
Rivaroxaban15 mg orally twice daily with food for 21 days, then 20 mg once daily with food; after at least 6 months, 10 mg once daily (or 20 mg once daily if recurrence risk is high).Check renal/hepatic function, interactions and bleeding. The 15 mg and 20 mg doses must be taken with food; contraindicated in pregnancy/breastfeeding.
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Sources and review status6 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NICE NG158: Venous thromboembolic diseases—recommendationsWells/D-dimer/ultrasound pathways, interim anticoagulation, treatment and duration.
  • NICE NG158 visual summaryTime-critical diagnostic algorithms.
  • eMC: Eliquis 5 mg SmPCApixaban DVT dosing and cautions.
  • eMC: Xarelto 20 mg SmPCRivaroxaban DVT dosing, food requirement and special populations.
  • eMC: Clexane SmPCEnoxaparin therapeutic dosing and renal adjustment.
  • eMC: Dabigatran 150 mg SmPCDVT/PE lead-in, adult dose, dose-reduction groups and renal contraindication.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom