10 Warning Signs of a Blood Clot in the Leg
A blood clot in a deep vein of the leg is called deep vein thrombosis (DVT). It can sometimes have no obvious symptoms, but common warning signs include:
- Swelling in one leg — especially sudden swelling of the calf, ankle, or thigh.
- Pain or tenderness — often in the calf or thigh and sometimes worse when walking or standing.
- Warmth — the affected area may feel noticeably warmer than the other leg.
- Red or discolored skin — the skin can appear red, purple, or darker than usual.
- A feeling of heaviness or tightness in the affected leg.
- Enlarged or more prominent veins near the surface of the skin.
- Calf cramping or aching that doesn’t have an obvious cause.
- Skin sensitivity or soreness when the area is touched.
- Symptoms affecting only one leg — DVT typically occurs on one side rather than both.
- Sudden worsening of symptoms — rapidly increasing swelling, pain, warmth, or discoloration deserves prompt medical attention.
🚨 When it’s an emergency
A clot can break loose and travel to the lungs, causing a pulmonary embolism (PE). Call emergency services immediately if you have possible DVT along with:
- Sudden shortness of breath
- Chest pain, particularly pain that worsens with breathing
- Coughing up blood
- Rapid or irregular heartbeat
- Severe dizziness, fainting, or collapse
Important: These symptoms can also be caused by other conditions, and you cannot reliably diagnose a blood clot from symptoms alone. If you develop new, unexplained swelling or pain in one leg, seek medical evaluation promptly.
