The diabetic may feel a numbness, usually in both feet, that moves up the leg as it becomes more severe. This numbness prevents the patient from realizing when their foot is rubbing the wrong way in a shoe or when they have a blister or cut. The loss of sensation is caused by high blood sugar, which causes damage to the nerves. Loss of sensation is usually permanent, but good blood sugar control often prevents it from getting worse. Dry, thickened foot skin Dry, thickened, and sometimes cracking skin is also the result of nerve damage caused by high blood sugar.
Nerve damage causes a loss of normal skin moisture.
Dry skin is likely to crack, allowing bacteria to get in and cause infection. Abnormal shape Nerve damage due to high blood sugar may cause a breakdown of the bones and joints of the foot. This results in deformity and loss of the normal shape of the foot. Ulcers Ulcers are basically just severe sores. Diabetics are more prone to developing ulcers, or common sores, than non-diabetics.