Diabetics are more prone to developing ulcers, or common sores, than non-diabetics. And diabetics that have had an ulcer before are at high risk for developing another ulcer. Because of the loss of sensation in the feet described above, a diabetic does not feel pain when a shoe is rubbing or a pebble in a shoe is irritating the foot and therefore does not solve the problem. A person with normal sensation would immediately remove the shoe or stop walking to prevent a serious sore from forming. In addition, because diabetics lose the ability to regulate moisture in their skin, the skin more readily develops cracks, leading to ulcers.
Diabetics are also at higher risk for infection of ulcers.
Diabetics have constricted blood vessels, which prevents normal blood flow to the feet. Lack of blood flow prevents the body from healing the ulcers effectively. These infections can sometimes only be treated with amputation. See below for ways to prevent the formation of ulcers. A common deformity of the toes may result from diabetes.