A blood clot in the legs is known as a very serious condition called deep venous thrombosis, or DVT. Because a blood clot in the legs can reduce blood circulation and increase the risk of developing a pulmonary embolism (a blood clot that travels to the lungs), the presence of a DVT indicates the need for emergency medical treatment.
Leg Pain and Tenderness
Pain and tenderness in one leg is a common symptom of deep venous thrombosis. When a blood clot forms in the leg, blood flow is blocked, which can cause pain. According to the American Academy of Family Physicians, this pain may only occur when standing or walking. Once a blood clot has been treated, lasting pain may occur. The National Institutes of Health defines this pain as post-phlebitic syndrome. After a DVT has been resolved, post-phlebitic syndrome may be prevented or resolved with the use of compression stockings, which reduce the pooling of blood in the veins.
Swelling
Swelling can occur at the site of a deep venous thrombosis because blood flow is reduced and blood is allowed to pool in the veins. Swelling caused by DVT can be seen as a change in the shape of the affected leg or an increase in the size of the leg. The University of Michigan Medical Center recommends elevating the affected leg and applying ice to the site of the swelling so swelling decreases. Avoiding prolonged sitting or standing can also prevent or reduce swelling. It is important to remember that a blood clot in the leg is dangerous. Do not try to treat this condition at home without seeking medical advice.
Redness and Warmth
Redness and warmth may also occur at the site of a deep venous thrombosis. This is due to the reduced blood flow at the site of a blood clot in the leg. When redness, warmth and other signs of a DVT occur, several tests can be ordered to make the diagnosis of deep venous thrombosis. According to the American Association for Clinical Chemistry, the D-dimer blood test can be used to determine if there has been excessive formation and breakdown of clots in the body. Doppler ultrasound can be done on the legs to determine if circulation is impaired due to the presence of a DVT. During this test, the direction and speed of blood cells are recorded as they travel through the blood vessels. This can help to determine if blood is moving slowly or not moving at all in specific areas of the leg.
