Diabetic Nerve Damage Can Mean Burning Pain or Feeling Nothing at All. It Is the Same Condition

Nerve damage is among the most common complications of diabetes and among the least consistently described, because it presents as two apparently opposite complaints.

Some people have relentless burning, tingling and electric-shock pain in the feet, worse at night, severe enough that the weight of a bedsheet is intolerable. Others have no sensation at all and only discover it when someone tests them, or when a wound appears that they never felt happen.

Same disease, same mechanism, opposite symptoms. And the painless version is the dangerous one, which is the exact reverse of how patients and often clinics prioritise it.

Why do the same nerves produce such different symptoms?

Because damaged nerves misfire before they fall silent.

The usual pattern, distal symmetric polyneuropathy, starts in the longest nerves, which are the ones reaching your feet. That is why it begins at the toes and works upward, and why it eventually appears in the fingers in what is described as a stocking and glove distribution.

An injured nerve that is still alive sends signals that were never triggered by anything. Your brain receives them and interprets them the only way it can, as burning or shooting pain in the foot. As damage progresses and the nerve stops conducting altogether, the false signals stop too. The pain fades.

Patients quite reasonably read that as improvement. It is usually progression, and it is the single most important misunderstanding in this area.

What is autonomic neuropathy?

The same process affecting the nerves that run things you do not consciously control, which is why it produces symptoms nobody connects to diabetes.

• Digestion. Gastroparesis slows stomach emptying, causing fullness, nausea and unpredictable glucose after meals because food arrives in the intestine on no reliable schedule. It is frequently mistaken for a dietary intolerance.
• Blood pressure. Damage to the nerves controlling vascular tone causes dizziness on standing, and falls in older patients that get attributed to age.
• The heart. Cardiac autonomic neuropathy can blunt the pain of a heart attack. A silent myocardial infarction is not a mild one, it is one that arrives without its warning.
• Hypoglycaemia awareness. The adrenaline symptoms that normally warn of a low, the shaking and sweating, are themselves nerve-mediated. Lose them and the first sign of a low may be confusion, which is a serious safety problem covered in our piece on recognising and treating lows.
• Sexual function. Erectile dysfunction is common in diabetes and often has a neuropathic and vascular basis rather than a psychological one. It is also, frequently, the earliest complication a man notices and the one he is least likely to mention.

Can it be reversed?

Largely, no, and the honest framing is prevention and management rather than repair.