National Blood Clot Alliance Addresses Misconceptions About Blood Clots

The National Blood Clot Alliance has addressed public concerns and misinformation surrounding blood clots, particularly in the wake of high-profile reports about NFL quarterback Jalen Hurts. The organization aims to separate fact from fiction and provide accurate information to the public.

According to the National Blood Clot Alliance, blood clots are far more common and deadly than most people realize. As many as 900,000 Americans are affected by blood clots each year, and as many as 100,000 die as a result. Despite these alarming statistics, public awareness remains dangerously low.

The alliance separates common misconceptions about blood clots. For instance, not all blood clots are the same. Blood clots in the veins can occur in the superficial or deep venous systems. A superficial vein thrombosis forms in a vein close to the surface of the skin, while a deep vein thrombosis (DVT) forms in a deeper vein, typically in the leg. Compared with superficial vein thrombosis, DVT carries a higher risk of causing a potentially life-threatening pulmonary embolism (PE), which can occur if part of a clot breaks off and travels to the lungs. A bilateral pulmonary embolism involves pulmonary arteries in both lungs.

Another misconception is that if a person can walk and exercise, they do not have a blood clot. The alliance emphasizes that a person’s ability to walk, exercise, or perform usual activities does not rule out a blood clot. Blood clots do not always cause immediate or severe symptoms, which is precisely what makes them dangerous. People may dismiss pain, swelling, or shortness of breath as a muscle strain or fatigue, sometimes with serious consequences. Symptoms and risk factors should be evaluated by a health care professional rather than assessed solely by a person’s ability to function.

The alliance also addresses the misconception that a superficial blood clot cannot become serious. It states that superficial vein thrombosis requires careful medical evaluation and follow-up. In some patients, it may occur at the same time as a DVT or extend toward or into the deep venous system. Patients should work with their physician to develop an appropriate follow-up and treatment plan based on their individual circumstances.

Another common misconception is that blood clot "movement" means it is traveling through the body. The alliance explains that terms such as "movement" are not precise medical descriptions and may have different meanings depending on the clinical and imaging context. They should not be interpreted without clarification from the treating medical team. In general, follow-up imaging may identify changes in a clot’s size, location, or extent that lead clinicians to reassess risk and treatment. Such language should not be used to draw conclusions about any individual patient’s condition.

The alliance also dispels the myth that blood clots only happen to people who are sick or sedentary. Blood clots can affect people of different ages and activity levels. Recognized risk factors may include trauma, long-distance travel, prolonged immobility, surgery, pregnancy, certain medications, cancer, and inherited or acquired clotting disorders. Some people have multiple risk factors, while in other cases no single cause is identified. The presence of a risk factor does not establish that it caused a particular person’s clot.

The alliance notes that lack of sleep alone is not a well-established direct cause of blood clots. Recognized risk factors include trauma, prolonged immobility, surgery, pregnancy, certain medications, and inherited or acquired clotting disorders. Although poor sleep can affect overall health, available evidence does not establish it as an independent direct cause of DVT or PE. Anyone concerned about blood-clot risk should speak with a health care professional about their individual circumstances.

The National Blood Clot Alliance urges anyone experiencing the following blood clot symptoms to seek immediate medical evaluation: S: Swelling in the leg, T: Tenderness, leg cramps, O: Out of breath, P: Pass out, C: Chest pain, back pain when breathing, L: Leg discoloration (red/blue hue), O: Overdrive, racing heart, T: Time to call 911.

The National Blood Clot Alliance, founded in 2003, is the leading national patient advocacy organization dedicated to preventing death and disability from blood clots, including deep vein thrombosis (DVT) and pulmonary embolism (PE). The organization advances its mission through public education, patient support, medical research, and legislative advocacy, working alongside patients, healthcare professionals, and policymakers to improve awareness, prevention, and care.