Diabetic Neuropathy

Diabetic peripheral neuropathy is nerve damage caused by diabetes. Persistent hyperglycemia drives metabolic injury, oxidative stress, advanced glycation end-product formation, and microvascular damage. Together, these processes injure peripheral nerve fibers. The longest nerves are usually affected first. Symptoms therefore begin in the toes and feet, then progress upward in a symmetric “stocking” pattern. Later, the hands may become involved in a “glove” distribution. A patient can have two apparently opposite symptom groups: - Irritated sensory fibers cause burning, electric, stabbing, tingling, or shooting pain. Even bed linens touching the feet may be painful. - Damaged sensory fibers cause reduced vibration, pressure, temperature, and pain sensation. The patient may not feel a blister, pebble in a shoe, heating pad burn, or developing ulcer. This distinction matters because less pain does not mean less injury. A painless plantar wound can be more dangerous than a painful one because the patient continues walking on it. Motor involvement may cause distal weakness, gait instability, or foot deformity. Autonomic neuropathy can affect blood pressure regulation and gastrointestinal motility, producing orthostatic symptoms or gastroparesis.