If one leg suddenly swells, feels tight and hurts when pressed, get medical care soon; if there is also sudden shortness of breath or chest pain, call 120 (China's ambulance number) at once
- High value
- Evidence B
- Buys life
- Costs a little
- Takes some hours
- No willpower
In a real emergency, call 911 first, then read this.
In plain words
If one leg suddenly swells, is clearly thicker than the other and hurts when pressed, get a leg vein ultrasound soon. If there is also sudden shortness of breath, chest pain on a deep breath, a fast heartbeat or dizziness, a clot may already have traveled to the lungs, so call 120 (China's ambulance number) straight away. Among people diagnosed with a pulmonary embolism, 17.4% died within 3 months. Sitting for more than 4 hours roughly doubles the risk, but for any one person it is still very low.
- Cost
-
An ultrasound of the leg's blood vessels (lower-limb venous ultrasound) costs one or two hundred CNY.
- What you get
-
The International Cooperative Pulmonary Embolism Registry (ICOPER) enrolled 2,454 patients with confirmed acute pulmonary embolism from 52 hospitals in 7 countries. A pulmonary embolism is a blood clot blocking the pulmonary artery. The death rate from all causes in this group within 3 months was 17.4% (426/2454). The World Health Organization's WRIGHT project: travel of 4 hours or more in a row "roughly doubles" the risk of a clot forming in a vein and traveling to the lungs (venous thromboembolism). But for any one person the chance is still very low, and for sitting without moving for more than 4 hours it is "about one in six thousand"
- Notes
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When both legs swell together, it is mostly a problem of the heart, liver, kidneys or vein function. One leg swelling suddenly and being clearly thicker than the other is the typical look of a deep vein thrombosis. Those at risk are people on long car or plane trips, people in bed after surgery or a fracture, people in a cast, women around pregnancy and childbirth, people with tumors, and people taking oral contraceptives. When a clot breaks off and blocks the pulmonary artery, it is a pulmonary embolism: sudden shortness of breath, more chest pain on a deep breath, a fast heartbeat, dizziness and coughing up blood (hemoptysis). At this point call 120 directly. The 17.4% is the death rate among confirmed pulmonary embolism cases, not the risk of "a swollen leg means this much danger," so don't frighten yourself with this figure.
- Evidence grade
- B : Supported by research but without a precise number, or based on small or single studies.
- Sources
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- Goldhaber SZ, Visani L, De Rosa M (1999). Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER). Lancet, 353(9162), 1386-1389. https://doi.org/10.1016/S0140-6736(98)07534-5
- WHO (2007). Study results released on travel and blood clots. https://www.who.int/news/item/29-06-2007-study-results-released-on-travel-and-blood-clots
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Translated from the Chinese original. Original book, section 13, tip 11. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer