A blood clot in a deep leg vein is one of the most common serious cardiovascular events people cannot name.
A U.S. Surgeon General's report estimated that at least 350,000 Americans are affected by deep vein thrombosis or pulmonary embolism each year. The two conditions combined may be responsible for more than 100,000 deaths a year.
Many of these clots stay silent until they cause serious harm. About 30 to 40 percent of DVT cases go unnoticed because they do not produce typical symptoms, NIH News in Health reports.
That is why the signs that do appear are worth learning to recognize. Deep vein thrombosis, or DVT, happens when a clot forms in a deep vein, most often in the calf or thigh. If the clot breaks loose, it can travel to the lungs and cause a life-threatening pulmonary embolism.
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The 7 warning signs to watch for
The Cleveland Clinic, the Mayo Clinic and NIH describe a small cluster of DVT symptoms that tend to appear on one side of the body.
1. Sudden swelling in one leg. Swelling that shows up in only one leg or arm, sometimes coming on quickly, is one of the most commonly reported early signs.
2. Pain or tenderness. Discomfort in the leg that can range from mild soreness to a deeper ache.
3. Cramping or a pulling sensation in the calf. Mayo Clinic describes leg pain, cramping or a pulling feeling that often begins in the calf.
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4. Warmth over the affected area. The skin over a swollen or painful spot may feel unusually warm to the touch.
5. Red or discolored skin. The affected area can look flushed, bluish or otherwise off-color.
6. Enlarged or bulging surface veins. Veins near the skin may look larger or more prominent than usual.
7. Pain that gets worse when you stand or walk. DVT discomfort may only become obvious once you put weight on the leg.
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Andrei Kindzelski, a blood disease expert at the NIH, sums up the classic pattern as swelling, pain, warmth and redness on the leg.
When to call 911
The most dangerous outcome is a pulmonary embolism, when part of the clot travels to the lungs. Cleveland Clinic reports that about one in three people with a pulmonary embolism die within a few hours of symptoms starting.
Call 911 if you notice sudden shortness of breath, sharp chest pain that gets worse when you breathe in or cough, coughing up blood, a rapid heartbeat, or feeling faint. These are pulmonary embolism warning signs, and quick treatment saves lives.
When to see your doctor
Not every swollen leg is a clot. Many other conditions cause the same symptoms, and only a minority of people with leg pain and swelling turn out to have DVT.
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Still, the message from health authorities is consistent. If a leg suddenly swells, warms or aches on one side without a clear reason, do not wait it out. Contact your doctor or go to the emergency room for evaluation.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.