Deep vein thrombosis (DVT)

Deep vein thrombosis (DVT) occurs when a blood clot (thrombus) forms in one or more of the deep veins in your body, usually in your legs. Deep vein thrombosis can cause leg pain or swelling, but may occur without any symptoms.

Deep vein thrombosis can develop if you have certain medical conditions that affect how your blood clots. Deep vein thrombosis can also happen if you don't move for a long time, such as after surgery, following an accident, or when you are confined to a hospital or nursing home bed.

Deep vein thrombosis is a serious condition because blood clots in your veins can break loose, travel through your bloodstream and lodge in your lungs, blocking blood flow (pulmonary embolism).

Symptoms Causes Risk factors Complications Prevention

Deep vein thrombosis signs and symptoms can include:

  • Swelling in the affected leg. Rarely, there may be swelling in both legs.
  • Pain in your leg. The pain often starts in your calf and can feel like cramping or a soreness.

Deep vein thrombosis may sometimes occur without any noticeable symptoms.

When to see a doctor

If you develop signs or symptoms of deep vein thrombosis, contact your doctor for guidance.

If you develop signs or symptoms of a pulmonary embolism — a life-threatening complication of deep vein thrombosis — seek medical attention immediately.

The warning signs of a pulmonary embolism include:

  • Unexplained sudden onset of shortness of breath
  • Chest pain or discomfort that worsens when you take a deep breath or when you cough
  • Feeling lightheaded or dizzy, or fainting
  • Rapid pulse
  • Coughing up blood

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