Upon hearing the term Factor Five Leiden, many question what is that? Factor V Leiden, or FVL for short, is when the clotting factor in your blood has been mutated. This mutation causes the person to be more likely to develop an abnormal blood clot in your veins. This leads to the question of what are the effects of FVL on a person? Factor V Leiden can affect someone physically, mentally/ emotionally, and socially. To begin, FVL can affect someone physically in many ways. It can affect someone by the loss of life. Some blood clots attributed to FVL can be deadly, depending on where they are in the body, and how soon it is brought to medical attention. Deep vein clots can cause swelling, redness, pain, and warmth. These symptoms can be disregarded