How Nerve Damage Can Lead to Diabetic Foot Ulcers

Foot problems are especially common in diabetics since multiple systems, especially the neurological and circulatory, are affected. Symptoms may first appear in the feet.

Neuropathy is a condition resulting from damage to the nerves. Not limited to individuals with diabetes, it remains a profoundly serious complication from elevated blood glucose over time.

Symptoms of neuropathy include burning, numbness, tingling or a feeling of fullness in the feet (as well as hands). In many instances, a partial or complete loss of sensation may occur. These are symptoms of peripheral neuropathy.

These are the obvious symptoms, however, and wasting of muscle strength from neuropathy may lead to imbalances and structural deformities, representing symptoms of autonomic neuropathy. Such deformities coupled with an altered gait from diminished proprioception (sense of self movement and body position) can lead to areas of increased pressure to underlying boney prominences during ambulation. Repetitive forces applied to an area of the foot that was not designed to bear weight during gait can lead to blisters and skin breakdown, also known as a diabetic foot ulcer.

Another cause of diabetic foot ulcer formation pertains to damage of the circulatory system. Chronic inflammation within the arteries of the body from elevated blood glucose leads to plaque formation (atherosclerosis) and decreased blood flow due to narrowing or blockage of the vessels. When this occurs outside of the heart vessels, and especially when found in the lower extremities, the condition is referred to as Peripheral Arterial Disease (P.A.D.). P.A.D. damages both the larger arteries which supply the structures within the legs and feet, and the small vessels that supply the skin.

The structural deformities of the feet which can occur in diabetics, begin with structural imbalances which may progress to deformities. Hammertoes, claw toes, and mallet toes are a few of the common ones.

In many instances, spontaneous fractures may occur in the foot, also related to neuropathy. This is referred to as a “Charcot Foot,” named after the French neurologist who first described the condition. Often there is no pain noted by the individual and the condition is frequently misdiagnosed as a sprain or infection. The individual may continue walking on a foot that has fractures within, and this can lead to further damage, including the collapse of the arch of the foot, along with multiple fractures which create a “rocker bottom sole.”  Secondary wounds are common with this type of foot condition as well as with the other potential deformities, as pressure points form in areas that nature did not intend.

The combination of both neurological and circulatory damage to the feet puts diabetics at high risk for developing ulcers, infection, amputation and even death.