The chronic elevation of plasma glucose profoundly affects traffic micro-vascular and macro-vascular circulation. The micro-vascular diseases associated with lost vision (retinopathy), renal (kidney) and loss of protective sensation in the muscle and sweat of the feet and hands (polyneuropathy). The macro-vascular diseases are associated with an increased incidence of stroke, coronary artery occlusions and a peripheral devascularization. All these vascular complications, direct or indirect, affect the management of diabetic foot problems.
The sensory neuropathy is the single factor most important in the development of ulcers, which in turn will lead to a foot infection, amputation as well as neuropathic fractures and sprains of the mid-foot (neuropathy Charcot). Loss of protective sensation may be confirmed by the patient’s inability to distinguish filaments Semmes-Weinstein 10 gm at any part of the foot. The motor neuropathy causes paralysis of intrinsic muscles and claw up toes, and a prominent plantar metatarsal heads high. In a 2nd time, the paralysis of the foot dorsal flexors causes foot drop with a steppage gait and secondary contracture of the calf muscles. The autonomic neuropathy leads to loss of sudo-motor function (sweating) and an arterio-venous shunt in the foot. Cracks or fissures, act as gateways to an infection that develops later in the very dry skin, while the AV shunt arterio-venous infusion decreases the oxygen level of the skin, hindering the healing of the ulcer.
As the condition develops, high levels of sugar in 
