Factor V Leiden is a mutation of a clotting factor in the blood named factor V, according to Mayo Clinic. Factor V Leiden may increase the risk of abnormal blood clots in the vein, but many people do not develop these abnormal clots.
Women have a higher risk of acquiring factor V Leiden during pregnancy or while taking estrogen, but the condition can occur in men and women, explains Mayo Clinic. Symptoms do not typically occur when factor V Leiden develops, but a development of a blood clot is usually the first symptom of the disorder. A clot that develops in a deep vein may not have any symptoms, but symptoms involving the legs such as pain, redness, swelling and warmth may occur. A clot forming near the surface of the skin may show symptoms such as tenderness around the affected vein, warmth and redness, and a clot in the lungs may cause chest pain, shortness of breath, rapid heartbeat and a bloody cough. Immediate medical attention is required if signs of a clot in a deep vein or lungs appear.
A combination of the blood-thinning medications heparin and warfarin is the first treatment typically used to treat blood clots caused by factor V Leiden, states Mayo Clinic. These blood-thinning medications are not used if no clots are present unless an individual is undergoing surgery or hospitalized. Pregnant women with factor V Leiden typically have normal pregnancies, but close monitoring is required throughout the pregnancy term.