Deep Vein Thrombosis (DVT)

Deep vein thrombosis is a serious condition where a blood clot forms in a deep vein, typically in the leg. These clots can break loose and travel to the lungs, causing a potentially fatal pulmonary embolism. DVT affects up to 900,000 Americans annually, with 60,000-100,000 deaths from venous thromboembolism. Early recognition and treatment are crucial to prevent complications and save lives.

🚨 Medical Emergency Warning

Seek immediate emergency care if you experience: sudden shortness of breath, chest pain that worsens with breathing, rapid pulse, coughing up blood, lightheadedness, or fainting. These may indicate a pulmonary embolism - a life-threatening complication of DVT.

Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any medical condition.

Understanding DVT

Deep vein thrombosis occurs when blood clots form in the deep venous system, most commonly in the lower extremities. Unlike superficial vein thrombosis, DVT poses significant risks because clots can dislodge and travel through the bloodstream to the lungs, heart, or brain.

Key Facts

  • Affects 1-2 per 1,000 people annually
  • Risk increases with age (1 in 100 over age 80)
  • 30% of patients develop post-thrombotic syndrome
  • 10-30% develop pulmonary embolism if untreated
  • Recurrence rate: 30% within 10 years
  • Can occur in upper extremities (4-10% of cases)

Virchow's Triad

Three factors contribute to thrombosis:

  1. Venous stasis: Slow blood flow
  2. Endothelial injury: Vessel wall damage
  3. Hypercoagulability: Increased clotting tendency

Signs and Symptoms

Common DVT Symptoms

  • Swelling: Usually in one leg, including ankle and foot
  • Pain: Often starts in calf, cramping or soreness
  • Warmth: Affected area feels warm to touch
  • Color changes: Red or bluish discoloration
  • Visible veins: Surface veins become more prominent
  • Leg fatigue: Heavy or tired feeling

Silent DVT

Up to 50% of DVT cases may be asymptomatic or have minimal symptoms, making diagnosis challenging. These "silent" clots are equally dangerous.

Pulmonary Embolism Symptoms

  • Sudden shortness of breath
  • Chest pain: Sharp, worse with deep breathing
  • Rapid heart rate
  • Coughing: May produce bloody sputum
  • Lightheadedness or fainting
  • Anxiety or feeling of doom
  • Excessive sweating

Upper Extremity DVT

  • Arm swelling
  • Pain in neck, shoulder, or arm
  • Bluish color of arm
  • Weakness of affected arm
  • Visible veins on chest/shoulder

Risk Factors

Major Risk Factors

  • Recent surgery: Especially orthopedic, abdominal, or pelvic
  • Hospitalization: Particularly with immobility
  • Active cancer: 4-7 times increased risk
  • Previous DVT/PE: 30% recurrence risk
  • Paralysis: Stroke, spinal cord injury
  • Major trauma: Multiple injuries, fractures

Moderate Risk Factors

  • Age: Risk doubles each decade after 40
  • Pregnancy and postpartum: 5-fold increased risk
  • Estrogen therapy: Birth control, HRT
  • Obesity: BMI >30
  • Long travel: >4 hours by plane/car
  • Central venous catheters
  • Inflammatory diseases: IBD, rheumatoid arthritis

Inherited Thrombophilias

  • Factor V Leiden mutation
  • Prothrombin gene mutation
  • Protein C deficiency
  • Protein S deficiency
  • Antithrombin deficiency
  • Antiphospholipid syndrome

Lifestyle Factors

  • Smoking
  • Dehydration
  • Sedentary lifestyle
  • Varicose veins

Diagnosis

Clinical Assessment

Wells Score for DVT

Clinical prediction rule (1 point each unless noted):

  • Active cancer
  • Paralysis or recent leg immobilization
  • Bedridden >3 days or surgery within 12 weeks
  • Tenderness along deep veins
  • Entire leg swollen
  • Calf swelling >3 cm compared to other leg
  • Pitting edema (greater in symptomatic leg)
  • Collateral superficial veins
  • Previous DVT
  • Alternative diagnosis as likely (-2 points)

Interpretation: Low risk (0), Moderate (1-2), High (≥3)

Laboratory Tests

  • D-dimer:
    • High sensitivity, low specificity
    • Normal level helps rule out DVT in low-risk patients
    • Elevated in many conditions
  • Complete blood count
  • Coagulation studies: PT/INR, aPTT
  • Thrombophilia testing: In selected cases

Imaging Studies

  • Compression ultrasonography:
    • First-line imaging test
    • 95% sensitive for proximal DVT
    • Less sensitive for calf vein thrombosis
  • Venography:
    • Gold standard but invasive
    • Rarely used today
  • CT or MR venography:
    • For pelvic or abdominal clots
    • When ultrasound inconclusive

Treatment

Anticoagulation Therapy

The cornerstone of DVT treatment is anticoagulation to prevent clot extension and embolization.

Direct Oral Anticoagulants (DOACs)

  • Apixaban (Eliquis): 10 mg twice daily x 7 days, then 5 mg twice daily
  • Rivaroxaban (Xarelto): 15 mg twice daily x 21 days, then 20 mg daily
  • Dabigatran (Pradaxa): After 5-10 days parenteral therapy
  • Edoxaban (Savaysa): After 5-10 days parenteral therapy

Traditional Anticoagulation

  • Low molecular weight heparin (LMWH):
    • Enoxaparin 1 mg/kg twice daily or 1.5 mg/kg daily
    • Preferred in cancer, pregnancy
  • Warfarin:
    • Target INR 2-3
    • Requires bridging with heparin
    • Regular monitoring needed

Duration of Treatment

  • Provoked DVT (surgery, trauma): 3 months
  • Unprovoked DVT: At least 3 months, consider extended
  • Cancer-associated: LMWH for 3-6 months, then reassess
  • Recurrent DVT: Indefinite anticoagulation

Thrombolytic Therapy

Reserved for:

  • Massive iliofemoral DVT
  • Phlegmasia cerulea dolens
  • Young patients with low bleeding risk
  • Symptom duration <14 days

IVC Filter

Indications:

  • Contraindication to anticoagulation
  • Failure of anticoagulation
  • Massive PE with poor reserve
  • Temporary use during high-risk periods

Supportive Care

  • Compression stockings: 30-40 mmHg, reduce post-thrombotic syndrome
  • Early ambulation: Safe with anticoagulation
  • Leg elevation: When resting
  • Pain management: Acetaminophen preferred

Prevention

Hospital-Based Prevention

  • Risk assessment: All admitted patients
  • Mechanical prophylaxis:
    • Sequential compression devices
    • Graduated compression stockings
    • Early mobilization
  • Pharmacologic prophylaxis:
    • LMWH or unfractionated heparin
    • Fondaparinux
    • DOACs in orthopedic surgery

Travel-Related Prevention

  • Move ankles and feet every 30 minutes
  • Walk every 1-2 hours on long flights
  • Stay well hydrated
  • Avoid alcohol and sedatives
  • Wear loose clothing
  • Consider compression stockings
  • High-risk individuals may need prophylactic anticoagulation

Lifestyle Modifications

  • Maintain healthy weight
  • Regular exercise
  • Stop smoking
  • Stay hydrated
  • Avoid prolonged immobility
  • Manage chronic conditions

Post-Surgery Prevention

  • Early mobilization
  • Compression devices during surgery
  • Prophylactic anticoagulation
  • Continue prophylaxis after discharge if high risk

Complications

Pulmonary Embolism

  • Occurs in 10-30% of untreated DVT
  • Can be fatal within hours
  • Requires immediate treatment
  • May cause chronic pulmonary hypertension

Post-Thrombotic Syndrome

  • Affects 20-50% of DVT patients
  • Symptoms:
    • Chronic leg pain
    • Swelling
    • Heaviness
    • Skin changes
    • Venous ulcers
  • Risk factors:
    • Proximal DVT
    • Recurrent DVT
    • Obesity
    • Older age

Chronic Venous Insufficiency

  • Damaged valves cause blood pooling
  • Skin discoloration
  • Venous stasis dermatitis
  • Ulceration in severe cases

Recurrent DVT

  • 30% risk within 10 years
  • Higher with unprovoked DVT
  • May require lifelong anticoagulation

Living with DVT

During Treatment

  • Take anticoagulation exactly as prescribed
  • Attend all follow-up appointments
  • Watch for signs of bleeding
  • Inform all healthcare providers about anticoagulation
  • Wear medical alert identification
  • Avoid activities with high injury risk

Dietary Considerations

  • On warfarin: Maintain consistent vitamin K intake
  • All anticoagulants: Limit alcohol
  • Stay well hydrated
  • Discuss supplements with doctor

Activity Guidelines

  • Walking encouraged once on anticoagulation
  • Avoid contact sports
  • Gradually increase activity
  • Elevate legs when resting
  • Wear compression stockings as directed

When to Seek Help

  • Signs of pulmonary embolism
  • Worsening leg symptoms
  • Signs of bleeding
  • Head trauma while on anticoagulation
  • Before any surgery or procedures

Prognosis

Short-Term Outlook

  • With treatment, most patients recover fully
  • Symptoms improve within days to weeks
  • Complete clot resolution in 3-6 months
  • Death rare with appropriate treatment (<1%)

Long-Term Outlook

  • Recurrence risk:
    • Provoked DVT: 3% at 5 years
    • Unprovoked DVT: 30% at 5 years
  • Post-thrombotic syndrome: 20-50%
  • Quality of life: Most return to normal activities

Factors Affecting Prognosis

  • Prompt treatment initiation
  • Clot location and extent
  • Underlying conditions
  • Medication adherence
  • Lifestyle modifications
  • Recurrence prevention measures