A blood clot in the leg (often called deep vein thrombosis, or DVT) can be serious because a clot may travel to the lungs and cause a pulmonary embolism. Knowing the warning signs can help you seek care sooner.
10 possible warning signs of a blood clot in the leg
- Swelling in one leg
- Especially when one calf, ankle, or thigh becomes noticeably larger than the other.
- Pain or tenderness
- Often felt in the calf or thigh and may feel like a cramp, soreness, or aching.
- Warmth over the affected area
- The skin may feel warmer than the surrounding area.
- Redness or discoloration
- The skin over the area may appear red, purple, or darker than usual.
- A feeling of heaviness or tightness
- The leg may feel unusually full, tight, or heavy.
- Pain that worsens when walking or standing
- Movement or pressure on the leg may increase discomfort.
- Visible surface veins
- Veins near the affected area may appear more prominent.
- Tenderness along a vein
- The area may hurt when touched.
- Sudden unexplained leg changes
- A new combination of swelling, pain, and color change should be taken seriously.
- Symptoms of a possible clot that has moved to the lungs
- Sudden shortness of breath
- Chest pain (especially with breathing)
- Coughing, sometimes with blood
- Fast heartbeat or feeling faint
Seek urgent medical help if:
- One leg suddenly becomes swollen, painful, warm, or red.
- You develop chest pain, breathing difficulty, fainting, or coughing blood.
Many conditions can cause leg pain or swelling (such as muscle injury, arthritis, or vein problems), so these signs do not always mean a clot—but new, unexplained symptoms should be evaluated promptly, especially if you have risk factors such as recent surgery, long periods of immobility, pregnancy/postpartum, cancer, or a previous clot.
