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 cause no symptoms, but common warning signs include:
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Swelling — usually in one leg, particularly the calf or thigh.
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Leg pain or tenderness — often felt in the calf and may worsen when walking or standing.
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Warmth — the affected area may feel noticeably warmer than the other leg.
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Red or discolored skin — the skin may appear red, purple, or darker than usual.
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A feeling of heaviness — the leg may feel unusually heavy or tight.
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Enlarged or prominent veins — veins near the skin can become more visible.
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Calf cramping or aching — persistent discomfort that doesn’t have an obvious explanation.
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Pain when flexing the foot — discomfort may occur when pulling the toes upward, although this sign alone is not a reliable way to diagnose DVT.
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One leg becoming noticeably different from the other — particularly in swelling, color, warmth, or circumference.
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Sudden or unexplained symptoms after a risk event — such as prolonged travel or immobility, recent surgery, injury, pregnancy/postpartum period, or certain medications. This doesn’t itself prove a clot, but it can increase concern.
🚨 When it’s an emergency
A clot can break loose and travel to the lungs, causing a pulmonary embolism (PE). Seek emergency medical care immediately if you have possible DVT symptoms together with:
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Sudden shortness of breath
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Chest pain, especially pain that worsens with breathing
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Coughing up blood
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Fainting or severe dizziness
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A rapid or irregular heartbeat
Important: These symptoms can have many other causes, and you cannot reliably diagnose a blood clot from symptoms alone. A healthcare professional may need to perform an examination and tests such as an ultrasound.
