Blood clots can form in the veins or arteries. Deep vein clots, called deep vein thrombosis, often occur in the lower leg or thigh, according to the National Heart Lung and Blood Institute. The clots pose a risk of breaking off and traveling through the vein to the heart and blocking arteries that carry blood to the lungs, which can be fatal. Blood clots can form in the arteries from the buildup of plaque and stop blood flow, resulting in possible death.
Pulmonary Embolism
A blood clot that breaks off and travels through the bloodstream to the lungs can block blood flow and cause pulmonary embolism. Blood clots in the thigh are more likely to cause pulmonary embolism, a serious condition that can result in death. Symptoms include shortness or breath, chest pain and discomfort, dizziness and coughing up blood. Symptoms of a blood clot include pain and swelling in the leg. The clots often develop from long periods of inactivity, such as sitting for an extended time because of travel or while recuperating from an injury. Medication can help dissolve the clots.
Post-phlebitic Syndrome
People who have recovered from deep vein thrombosis risk developing a condition called post-phlebitic syndrome, according to MayoClinic.com. Also known as post-thrombotic syndrome, the condition results from damage to the veins from blood clots. Blood flow becomes reduced in the affected areas. Symptoms may include swelling of the legs, leg pain and skin discoloration and can occur a few years after having deep vein thrombosis. Medication can treat the condition. Some people at risk for developing clots wear compression stockings worn up to the knee to reduce swelling and help prevent more clots from forming. They may wear the stockings for up to a year.
Cardiovascular Disease
Blood clots that form in the arteries are not detected until serious damage occurs and they can cause sudden heart attack or stroke. Heart disease occurs because of the buildup of plaque from cholesterol and other fats, narrowing the arteries and interfering with blood flow. Many people do not realize they have heart disease until tested. Others may find out because of chest pains, or angina, caused by reduced blood flow. Clots can form on the plaque and eventually block blood flow completely. Blockage of arteries to the heart can cause heart attack because the heart begins to die, the American Heart Association notes. Blockage of blood flow in arteries that feed the brain can kill brain cells and cause a stroke.
