A blood clot in a deep vein of the leg—known as Deep vein thrombosis—can be serious because part of the clot can travel to the lungs and cause a Pulmonary embolism.
Here are 10 possible warning signs:
- Swelling in one leg, especially if it develops suddenly.
- Pain or tenderness, often starting in the calf and sometimes described as a cramp or soreness.
- Warmth in the affected area compared with the other leg.
- Red or discolored skin over the painful area.
- A feeling of tightness or fullness in the calf or thigh.
- Pain that gets worse when standing or walking, though it can also occur at rest.
- Enlarged or more visible surface veins in the affected leg.
- Tenderness when the affected area is touched, particularly along the course of a deep vein.
- Leg heaviness or fatigue that is new and confined to one leg.
- No obvious injury to explain these symptoms. A clot can occur without a muscle strain or other trauma.
It’s important to know that some people with DVT have few or no symptoms, so the absence of these signs does not rule it out.
Seek emergency care immediately if you have leg symptoms plus any of these:
- Sudden shortness of breath
- Chest pain, especially if it worsens with breathing
- Coughing up blood
- Fainting or feeling like you might pass out
These could indicate a pulmonary embolism, which is a medical emergency.
Risk factors for DVT include:
- Recent surgery or hospitalization
- Prolonged immobility (such as long flights or bed rest)
- Pregnancy and the weeks after childbirth
- Certain cancers
- Estrogen-containing birth control or hormone therapy
- Previous DVT or PE
- Increasing age
- Smoking
- Obesity
- Some inherited clotting disorders
A healthcare professional typically diagnoses DVT using a combination of your symptoms, risk factors, blood tests in some cases, and an ultrasound of the leg. If you think you may have a DVT, seek prompt medical evaluation, as early treatment can reduce the risk of complications.
