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Cardiology

Deep Vein Thrombosis: Recognizing and Preventing Blood Clots

Deep vein thrombosis (DVT) is a blood clot in a deep vein, usually in the legs. If the clot breaks loose and travels to the lungs, it causes pulmonary embolism—a life-threatening emergency. Knowing risk factors and symptoms can save your life.

ICD Code: I82.4

Understanding Deep Vein Thrombosis

Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, usually in the leg or pelvis. The clot blocks blood flow and causes swelling and pain. The real danger? The clot can break loose, travel through the bloodstream, and lodge in the lungs—causing pulmonary embolism (PE), which can be fatal.

Think of your veins like highways returning blood to the heart. When a clot forms (like a traffic accident), flow backs up, causing swelling. If part of that clot breaks loose (like debris from the accident), it travels downstream and can cause a blockage elsewhere—in this case, the lungs.

DVT and PE Are the Same Disease

DVT and PE are collectively called venous thromboembolism (VTE)—two manifestations of the same disease process.Kearon et al. Chest, 2021 DVT is the clot in the vein; PE is when that clot (or piece of it) travels to the lungs. Up to 30% of untreated DVTs lead to PE. Think of DVT as the source and PE as the complication.

Recognizing DVT Symptoms

Typical DVT Symptoms:

  • Swelling in one leg (usually calf or thigh)
  • Pain or tenderness, often starting in calf
  • Redness or warmth over the affected area
  • Visible veins (surface veins may become prominent)
  • Leg feels heavy or full

Important:

  • Usually affects ONE leg (bilateral swelling suggests other cause)
  • Can be painless (especially in large DVTs)
  • May occur without obvious symptoms (silent DVT)

When to Seek Medical Attention

Potential DVT - Seek Care Promptly

Contact your doctor or go to urgent care if:

  • Unexplained swelling in one leg (especially calf or thigh)
  • Pain or tenderness in one leg, especially calf
  • Redness or warmth over a leg vein
  • Heavy or aching sensation in one leg

Call 911 or go to ER if you ALSO have:

  • Chest pain or shortness of breath: Possible pulmonary embolism
  • Coughing up blood: Possible PE
  • Rapid heart rate or breathing: Sign of PE
  • Feeling faint or passing out: Sign of PE

These PE symptoms are life-threatening emergencies.

DVT Treatment: Preventing PE and Recurrence

DVT Treatment Approach

FactorEffectWhat to Do

Always tell your doctor about medications, supplements, and recent health events before testing.

Post-Thrombotic Syndrome: The Long-Term Complication

Up to 50% of people with DVT develop post-thrombotic syndrome (PTS):

  • Chronic leg pain, swelling, and heaviness
  • Skin changes: discoloration, thickening, ulcers
  • Varicose veins
  • Reduced quality of life

Preventing Post-Thrombotic Syndrome

PTS is caused by permanent vein damage from the DVT. Prevention strategies:

  • Wear compression stockings as prescribed
  • Complete full course of anticoagulation
  • Elevate legs when possible
  • Regular exercise (walking is excellent)
  • Maintain healthy weight
  • Avoid prolonged standing or sitting

Prevention: DVT Is Often Preventable

DVT Prevention Strategies

  • After surgery: Early mobilization, compression devices, prophylactic anticoagulation as prescribed
  • During hospitalization: Ask about DVT prophylaxis (blood thinners or compression devices)
  • During travel: Move regularly, stay hydrated, avoid alcohol, consider compression socks for long flights
  • If high risk: Discuss prophylaxis with your doctor before high-risk situations
  • Lifestyle: Maintain healthy weight, stay active, don't smoke

Special Situations

Pregnancy:

  • 5-10x increased DVT risk
  • Low molecular weight heparin (not warfarin) is treatment of choice
  • Anticoagulation continues for 6 weeks postpartum minimum

Cancer:

  • Cancer increases clotting risk 4-7x
  • DVT may be first sign of undiagnosed cancer
  • DOACs or low molecular weight heparin used
  • Anticoagulation continues while cancer active

Travel-Related:

  • Risk increases after ＞4 hours of immobility
  • Move regularly, stay hydrated, avoid alcohol
  • Consider compression socks if high risk

Long-Term Outlook

Related Conditions

FAQ

References

References

  • [1]2021 CHEST Guidelines for Venous Thromboembolism. Chest. https://www.chestjournal.org/article/S0012-3692(21)00362-6
  • [2]2016 ACCP Guidelines for DVT Treatment. Chest. https://www.chestjournal.org/article/S0012-3692(16)00342-7
  • [3]2023 ASH Guidelines for Management of Venous Thromboembolism. Blood. https://ashpublications.org/blood/article/141/24/2797/499337
  • [4]Kearon C et al. Antithrombotic Therapy for VTE Disease. Chest, 2021. https://www.chestjournal.org/article/S0012-3692(21)00377-8
  • [5]Riva N et al. Direct Oral Anticoagulants for VTE. New England Journal of Medicine, 2020. https://doi.org/10.1056/NEJMra2005423
  • [6]Becattini C et al. Post-Thrombotic Syndrome Prevention. Circulation, 2022. https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.121.056245
  • [7]Centers for Disease Control and Prevention. DVT Facts and Prevention. https://www.cdc.gov/ncbddd/dvt/index.html
  • [8]American Heart Association. Venous Thromboembolism Statistics. https://www.heart.org/en/health-topics/venous-thromboembolism
  • [9]NIH. Venous Thromboembolism Research. https://www.nhlbi.nih.gov/health-topics/venous-thromboembolism
  • [10]ISTH Guidelines for Venous Thromboembolism. Journal of Thrombosis and Haemostasis. https://onlinelibrary.wiley.com/journal/15387836

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Deep Vein Thrombosis: Recognizing and Preventing Blood Clots | Disease Guide