Diabetic Neuropathy: How High Blood Sugar Damages Nerve Sheaths

 

See the video below for a demonstration of how high blood sugar damages nerves and the myelin sheath.

Watch how uncontrolled diabetes damages nerves over time, leading to tingling, burning pain, numbness, and weakness in the hands and feet.

Diabetic neuropathy is one of the most common — and most under-recognized — complications of uncontrolled diabetes. This illustration shows what actually happens at the nerve level when blood sugar stays high for a prolonged period.

Nerves are covered by a protective layer called the myelin sheath, which allows electrical signals to travel quickly and accurately between the brain and the rest of the body. Chronic high glucose damages small blood vessels that supply the nerves (a condition called microangiopathy), starving the nerve fibers of oxygen and nutrients. Over time, this breaks down the myelin sheath and injures the nerve fibers themselves.

The result is a gradual loss of sensation, tingling, burning pain, and weakness — most commonly starting in the feet and hands ("stocking-glove" pattern). Left unmanaged, this can progress to numbness severe enough that patients don't notice cuts or wounds, significantly raising the risk of diabetic foot ulcers and infections.

Early blood sugar control, regular foot checks, and prompt treatment of symptoms can slow or even halt this nerve damage.