This occurs when arteries in the legs become clogged with plaque. The blood flow is then reduced to the feet. This can cause legs to swell, turn red, and potentially cause ulcers/sores on the feet and legs. If not treated properly these foot/leg ulcers can result in amputation. If the arteries are clogged in the legs, the arteries close to the heart may be clogged as well. This is a very important condition to diagnose and treat promptly.