Overview
Why a Small Foot Injury Can Become Limb-Threatening
A diabetic foot ulcer usually begins with a problem the patient does not feel.
A diabetic foot ulcer usually begins with a problem the patient does not feel. Peripheral neuropathy reduces protective sensation, so a pebble in a shoe, a blister, or repeated pressure beneath a metatarsal head may continue unnoticed. Motor neuropathy changes foot mechanics over time, creating claw toes, prominent metatarsal heads, or a high-pressure plantar surface. Autonomic neuropathy decreases sweating, leaving dry, fissured skin that breaks more easily. Peripheral arterial disease adds a second problem: inadequate blood flow. Tissue with poor perfusion tolerates pressure poorly, heals slowly, and has less ability to contain infection. Hyperglycemia further impairs leukocyte function and wound repair. The result is a dangerous combination: repetitive trauma, reduced warning pain, impaired healing, and infection that may advance farther than the skin appearance suggests. A patient may say, “It does not hurt,” while having a deep ulcer. In diabetes, lack of pain is not reassuring.