A blood clot occurs when blood congeals. If this happens inside a person’s body, including their leg, it can cause severe problems. Some blood clots are especially dangerous as they can travel to a person’s lungs, causing a pulmonary embolism that can be fatal.
The Agency for Healthcare Research and Quality (AHRQ) note that the symptoms of a blood clot in a person’s leg include swelling, red skin, pain in the leg, or the leg feeling warm to the touch. According to the Centers for Disease Control and Prevention (CDC), if a blood clot happens in a larger vein, this is a deep vein thrombosis (DVT).
The AHRQ say that blood clots are more likely to occur if a person is unable to move around a lot. This can be due to surgery, an injury, or sitting down for an extended period, such as on a long-haul flight.

According to the
Symptoms include:
- Swelling: If a person develops a clot in their leg, it may swell up so that it is much larger than the other leg.
- Red skin: The skin on their leg may also become red or discolored.
- Pain: They may experience pain in the part of the leg where the blood clot has developed.
- Warmth: The swollen, red skin may feel warm to the touch.
According to the
The symptoms of a pulmonary embolism include:
- shortness of breath
- pain when breathing
- rapid breathing
- increased heart rate
A pulmonary embolism is a life-threatening condition that requires immediate emergency treatment.
According to the AHRQ, risk factors for a blood clot include:
- having had surgery recently
- being older than 65
- taking birth control hormones
- being treated for cancer, or having had cancer
- having a broken hip, pelvis, or leg
- having a bad bruise
- being obese
- staying seated or in bed for long periods
- having had a stroke
- being paralyzed
- having a port in their body through which a doctor administers medicine
- having issues with veins
- having heart problems
- having had a blood clot previously, or family members who have had blood clots
According to the
The CDC also recommend that a person gets up and walks around regularly, and exercises their leg muscles, even when seated.
A person could try:
- raising and lowering their heels while keeping their toes on the floor
- raising and lowering their toes, keeping their heels on the floor
- tightening and releasing their leg muscles
According to an article in the Journal of Thrombosis and Haemostasis, taking a low dose of aspirin might be effective at reducing the chances of developing blood clots or DVT.
It is possible to minimize the risk of developing a blood clot or DVT by avoiding clear risk factors and practicing prevention techniques, such as exercising muscles wherever possible.
If a person thinks they have had a blood clot in their leg, they should contact a doctor immediately.