Factor V Leiden is a genetic mutation that affects the blood’s ability to clot properly, leading to an increased tendency for abnormal blood clot formation. The complications of Factor V Leiden primarily stem from this heightened risk of thrombosis, which means blood clots forming in veins or arteries where they shouldn’t. These clots can cause a range of serious health issues depending on their location and severity.
One of the most common and significant complications is **deep vein thrombosis (DVT)**. This occurs when a clot forms in the deep veins, usually in the legs. Symptoms of DVT include swelling, pain, warmth, and redness in the affected limb. If untreated, these clots can grow or break off and travel through the bloodstream, leading to more dangerous conditions.
A particularly dangerous complication is **pulmonary embolism (PE)**, which happens when a clot from a deep vein travels to the lungs and blocks blood flow. This can cause sudden shortness of breath, chest pain that worsens with breathing, rapid heart rate, and even coughing up blood. Pulmonary embolism can be life-threatening and requires immediate medical attention.
Factor V Leiden also increases the risk of **stroke** and other arterial clots, although this is less common than venous clots. A stroke caused by a clot can lead to dizziness, weakness, speech difficulties, and other neurological symptoms depending on the part of the brain affected.
In women, Factor V Leiden carries additional risks related to pregnancy. It is associated with complications such as **preeclampsia**, which is high blood pressure during pregnancy that can harm both mother and baby; **placental abruption**, where the placenta detaches prematurely from the uterus; and **fetal growth restriction**, where the baby does not grow properly in the womb. These complications can lead to miscarriage, stillbirth, or preterm birth.
People with Factor V Leiden who use **oral contraceptives or hormone replacement therapy** face an even higher risk of clotting complications because these medications can further increase blood clotting tendencies.
Other complications include recurrent thrombosis, where individuals experience multiple episodes of clot formation over time, increasing the risk of long-term damage to veins and organs. Chronic venous insufficiency can develop if clots damage the veins, leading to persistent swelling, pain, and skin changes in the affected limbs.
In rare cases, Factor V Leiden can contribute to **cerebral venous sinus thrombosis**, a clot in the veins draining blood from the brain, causing headaches, vision problems, seizures, or stroke-like symptoms.
Because Factor V Leiden raises the risk of clot formation, it can complicate surgeries, prolonged immobilization (like long flights or bed rest), and other medical conditions that predispose to clotting. Managing these risks often requires careful monitoring and sometimes preventive blood-thinning medications.
Overall, the complications of Factor V Leiden revolve around the formation of abnormal blood clots that can block blood flow in veins or arteries, leading to potentially serious and life-threatening conditions affecting the lungs, brain, legs, and pregnancy outcomes. Recognizing symptoms early and managing risk factors is crucial to preventing these complications.
