Infections, nerve damage, circulatory problems and muscle abnormalities can cause sores or ulcers on the feet, according to Drugs.com. Raynaud's phenomenon is a condition in which blood flow to the fingers and toes decreases for periods of time, causing infections that can lead to foot ulcers.
One of the most common causes of foot sores and ulcers is diabetes, a disease that causes nerve damage in the feet and reduces circulation, explains Drugs.com. Smalls sores can turn into serious infections that can result in amputations if left untreated. An ulcer or open sore in the foot can become infected, eventually turning into a pus-filled abscess. This abscess can then spread throughout the skin and fat layer of the foot before eventually reaching the bone. Finally, the tissue dies, and gangrene sets in, which may require an amputation of the foot or even the leg.
Individuals who have peripheral neuropathy or nerve damage, diabetes, or circulatory problems need to take care of their feet, advises Drugs.com. They should avoid wearing tight shoes than can rub open a sore on the feet, and they need to examine their feet regularly to see if they have any injuries or sores. When nerve damage sets in to the feet, patients can find it difficult to feel any injuries occur because of nerve numbness.