 Up to 900,000 men, women, and children are affected by blood clots each year, and about 100,000 die from them. Blood clots don't discriminate. You or a loved one could be at risk right now. The good news is blood clots can be prevented. Knowing the risks and symptoms are key. Major risks for blood clots include a family or personal history of blood clots, a recent hospitalization or surgery, pregnancy and cancer and its treatments. Symptoms of a blood clot in the legs or arms can include pain, swelling, and skin that is warm to the touch, red or discolored.