Deep vein thrombosis (DVT)

Deep vein thrombosis (DVT) is a condition in which 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, but often occurs without any symptoms.

Deep vein thrombosis can develop if you're sitting still for a long time, such as when traveling by plane or car, or if you have certain medical conditions that affect how your blood clots.

Deep vein thrombosis is a serious condition because a blood clot that has formed in your vein can break loose and travel to your lungs. However, many deep vein thromboses disappear on their own.

In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms.

When signs and symptoms of deep vein thrombosis occur, they can include:

* Swelling in the affected leg, including swelling in your ankle and foot.
* Pain in your leg; this can include pain in your ankle and foot. This pain often starts in your calf and can feel like cramping or a "charley horse."
* Redness and warmth over the affected area.
* Pain or swelling in your arms or neck. This can occur if a blood clot forms in your arms or neck.

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
* Coughing up blood
* A sense of anxiety or nervousness