A blood clot in the leg, often called a deep vein thrombosis (DVT), happens when a clot forms in a deep vein, usually in the calf or thigh. A DVT can be dangerous because part of the clot can travel to the lungs and cause a pulmonary embolism, which is a medical emergency.
10 Warning Signs of a Possible Leg Blood Clot
- Swelling in one leg
- Often affects one side and may involve the calf, ankle, or entire leg.
- Leg pain or tenderness
- Pain may feel like a cramp, soreness, or aching, especially in the calf.
- Warmth in the affected area
- The skin over the clot may feel warmer than the surrounding area.
- Redness or discoloration
- The skin may appear red, darker, or have a changed color.
- A feeling of heaviness or tightness
- The leg may feel unusually heavy, full, or tense.
- Visible swelling of veins
- Surface veins may appear more prominent.
- Pain that worsens when walking or standing
- Movement may increase discomfort.
- Unexplained leg swelling after long periods of immobility
- Risk can increase after long travel, surgery, bed rest, or prolonged sitting.
- Sudden shortness of breath (possible clot reaching the lungs)
- This requires urgent medical attention.
- Chest pain, coughing (sometimes with blood), or rapid heartbeat
- These can be signs of a pulmonary embolism and need emergency care.
Seek urgent medical help if:
- One leg suddenly becomes swollen, painful, warm, or red.
- You develop chest pain, trouble breathing, fainting, or coughing blood.
Risk factors for DVT include:
- Recent surgery or hospitalization
- Long periods of sitting or immobility
- Previous blood clots
- Smoking
- Certain cancers or medical conditions
- Pregnancy or hormone medications
- Increasing age
Leg symptoms can have many causes, and only a healthcare professional with appropriate testing (such as an ultrasound) can confirm a blood clot. If you describe your symptoms—which leg, where the pain is, when it started, and whether there is swelling or redness—I can help you understand how concerning it sounds.
