MEDICOMEDICS
Get started

Cardiology

Deep Vein Thrombosis (DVT)

Thrombus in deep veins, usually of the lower limb. Risk = Virchow triad. Presents with unilateral leg swelling and pain; diagnosed by compression ultrasound and treated with anticoagulation.

Last reviewed 23 May 2026 - MedicoMedics editorial team

Thrombus formation in a deep vein of the leg causing DVT

Pathophysiology

Virchow triad: venous stasis (immobility, prolonged travel, surgery), endothelial injury (trauma, catheter) and hypercoagulability (malignancy, oestrogen, pregnancy, factor V Leiden, prothrombin G20210A, protein C/S or antithrombin deficiency, antiphospholipid syndrome). Thrombus most commonly forms in the calf then propagates proximally.

Sources: CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545); ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Clinical presentation

Unilateral leg swelling, calf pain, warmth, erythema, palpable cord along the vein, positive Homans sign (insensitive). Massive iliofemoral DVT: phlegmasia cerulea dolens (blue, painful, compromised limb). Silent presentation is common in postoperative and hospitalised patients.

Sources: CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545); ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Diagnosis

Use Wells score. Low pretest probability + negative D-dimer excludes DVT. Otherwise, compression ultrasound with Doppler is first-line - non-compressible vein is diagnostic. Repeat ultrasound at 5-7 days if initially negative but suspicion remains. CT venography or MR venography reserved for pelvic/IVC assessment (e.g. May-Thurner syndrome).

Sources: CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545); ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Management

Immediate anticoagulation with DOAC (rivaroxaban or apixaban with loading regimen) or LMWH bridging to warfarin (INR 2-3). Cancer-associated DVT: DOAC (apixaban, edoxaban) or LMWH. Minimum 3 months for provoked, longer or indefinite for unprovoked or recurrent. Compression stockings for symptom relief. Thrombolysis (catheter-directed) or thrombectomy for phlegmasia or extensive iliofemoral DVT.

Sources: CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545); ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Prevention & complications

VTE prophylaxis (mechanical + LMWH or DOAC) for hospitalised, surgical and postpartum patients. Complications: pulmonary embolism, post-thrombotic syndrome (chronic swelling, pain, ulceration), chronic thromboembolic pulmonary hypertension. Consider thrombophilia workup if unprovoked in young patient, strong family history or recurrent VTE.

Sources: CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545); ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Sample USMLE-style MCQs

Try 10 questions on this topic. Practice hundreds more free with a trial.

Question 1

Which ultrasound finding is diagnostic of DVT?

Question 2

A patient with unprovoked proximal DVT. Duration of anticoagulation?

Question 3

A 24-year-old woman on combined oral contraceptive develops recurrent left-leg DVT. What anatomic variant should be considered?

Question 4

A patient with unprovoked DVT and no bleeding risk should be anticoagulated for?

Question 5

First-line DOAC after acute DVT?

Question 6

When is D-dimer clinically useful?

Question 7

Which is a contraindication to DOAC in DVT?

Question 8

Best imaging for suspected proximal DVT?

Question 9

Which cancer-associated DVT regimen is preferred first-line?

Question 10

Cancer-associated VTE treatment of choice?

References

Primary guidelines and peer-reviewed sources used for this entry. Reviewed 23 May 2026 by MedicoMedics editorial team.

  1. CHEST 2021 Antithrombotic Therapy for VTE (CHEST 2021;160:e545)
  2. ASH 2020 Guidelines on VTE (Blood Adv 2020;4:4693)

Frequently asked

What is May-Thurner syndrome?

Compression of the left common iliac vein by the right common iliac artery, causing recurrent left-leg DVT in young women.

When is an IVC filter appropriate?

When anticoagulation is absolutely contraindicated or DVT/PE recurs on adequate therapy - preferably retrievable filters that are removed once anticoagulation resumes.

Why choose DOACs over warfarin?

DOACs offer predictable pharmacokinetics without monitoring, fewer major bleeds and no dietary interactions - warfarin remains preferred for antiphospholipid syndrome and mechanical valves.

What defines post-thrombotic syndrome?

Chronic pain, swelling, hyperpigmentation and ulceration of the affected limb after DVT due to valvular incompetence and venous hypertension.

Related conditions

High-yield topics students commonly study alongside Deep Vein Thrombosis (DVT).

More in Cardiology

Ready to master this topic?

Get the full lecture, 500+ MCQs, and AI explanations with a 7-day free trial.

Start free trialBack to library