Factor V Leiden is a mutation of one of the clotting factors in the blood called factor V. This mutation can increase your chance of developing abnormal blood clots (thrombophilia), usually in your veins. Most people with factor V Leiden (FAK-tur five LIDE-n) never develop abnormal clots. But some do develop clots that lead to long-term health problems or become life-threatening. Both men and women can have factor V Leiden. Women may have an increased tendency to develop blood clots during pregnancy or when taking the hormone estrogen. If you have factor V Leiden and have developed blood clots, anticoagulant medications can lessen your risk of developing additional blood clots and help you avoid potentially serious complications. Most people who have factor V Leiden never develop signs or symptoms. The first indication that you have the disorder may be the development of a blood clot (thrombosis). Some clots do no damage and disappear on their own.
Others can be life-threatening. Symptoms of a blood clot depend on where it forms and whether and where it travels. A clot in a deep vein this is known as deep vein thrombosis (DVT). Deep vein thrombosis may not cause any symptoms. If signs and symptoms do occur, they commonly affect your legs, including swelling of your ankles and feet. Other signs and symptoms may include pain, significant swelling, redness, warmth. A clot closer to the surface of your skin this is referred to as superficial venous thrombosis, phlebitis or thrombophlebitis. Signs and symptoms usually include warmth, tenderness or pain, often in or around the vein with the blood clot, redness A clot that travels to your lungs known as a pulmonary embolism, this occurs when a deep vein clot breaks free and travels through the right side of your heart to your lung, where it blocks blood flow. This can be a life-threatening situation. Signs and symptoms may include sudden shortness of breath, chest pain when breathing in, a cough that produces bloody or blood-streaked sputum, tachycardia The chance of developing an abnormal blood clot depends on whether a person has one or two copies of the factor V Leiden mutation in each cell. People who inherit two copies of the mutation, one from each parent, have a higher risk of developing a clot than people who inherit one copy of the mutation.
Considering that about 1 in 1,000 people per year in the general population will develop an abnormal blood clot, the presence of one copy of the factor V Leiden mutation increases that risk to 3 to 8 in 1,000, and having two copies of the mutation may raise the risk to as high as 80 in 1,000. Treatment People with factor V Leiden who have had a DVT or PE are usually treated with blood thinners, or anticoagulants.
Anticoagulants such as heparin are given for varying amounts of time depending on the person's situation. It is not usually recommended that people with factor V Leiden be treated lifelong with anticoagulants if they have had only one DVT or PE, unless there are additional risk factors present.