Pressure ulcers are sores that occur when pressure cuts off the blood supply to the skin.
The stress that is caused by the body's weight, and the impact of the foot striking the ground can place the big toe, the heel and the ball of the foot at greatest risk for pressure ulcers. If left untreated, an ulcer may allow infection to enter your body. If the infection reaches the bloodstream or bone, your life or limb may be at risk. With your doctor's help, pressure ulcers can be controlled and even prevented. Force or friction against the bottom of your foot causes the skin to thicken, forming a callus.