Peripheral neuropathy is the most common type of diabetic neuropathy.
Sensory nerves allow the brain to respond to pain, touch, temperature, and vibration. Motor nerves work in concert with muscles to control movement. When diabetes damages sensory nerves, peripheral neuropathy occurs. Peripheral neuropathy may also damage the motor nerves.
The effects and symptoms of peripheral neuropathy progress slowly, over a period of months to years. The first symptoms are usually a mild burning sensation in the affected area. If high blood glucose levels are maintained over several years, the burning sensation increases dramatically and then slowly disappears. This is followed by a numbness that makes it more likely that the patient will damage the affected area.
Peripheral neuropathy can occur in almost any part of the body. The foot and legs are the most common sites of onset. Loss of protective sensation in the foot and a diminished ability to feel pain can lead to the formation of calluses and blisters, bone and joint problems, infections, and foot ulcers. Minor repetitive injuries to the foot, such as those caused by ill-fitting shoes, can lead to greater problems because the patient does not feel the pain and injury. Reduced sensation in the foot can also change a patient’s gait and lead to bone or joint problems. If left untreated, foot problems can worsen, leading to the need for amputation of the foot or lower leg.