What it feels like, and where it starts

Peripheral neuropathy shows up first in the longest nerves in the body, which is why it starts in the feet and climbs — a stocking-glove pattern, burning or electric at rest, numb enough that patients step on things without noticing, and unsteady enough that falls become a real risk before pain ever does. Diabetic neuropathy is the most common cause we see, but prediabetes, alcohol, chemotherapy, autoimmune disease, and B12 deficiency all damage the same small fibers by different routes, which is why the workup does not stop at a glucose number.

The mechanism underneath the burning

Two biological drivers do most of the damage. The first is hyperinsulinemia and insulin resistance themselves — years of elevated insulin, not just elevated glucose, injure nerve fibers directly and predict neuropathy even in patients whose blood sugar looks acceptable on paper. The second is a combined microvascular and mitochondrial failure: the small vessels feeding the nerve narrow and stiffen, starving the fiber of oxygen, while the mitochondria inside the nerve cell lose their capacity to buffer the resulting oxidative stress. The nerve is, quite literally, running out of both fuel and the machinery to burn it cleanly. The third driver is economic and behavioral: the diet that reverses insulin resistance costs more and takes more time than the diet that caused it, and a patient working two jobs on a fixed income is not choosing neuropathy, they are choosing the food and the schedule available to them. We do not treat that as a footnote.

I spent the first twenty years of my career telling patients their A1C was “not too bad” because it sat just under the diabetes cutoff. I was wrong. The nerve damage in prediabetes starts well before that line, and by the time a chart says diabetic, the small fibers have often been losing ground for years. That changed how early we look now.

What we measure

Beyond the exam — monofilament testing for light touch, vibration sense, reflexes, and a look at gait and balance — bloodwork is part of the first visit, not an add-on: fasting insulin and HbA1c at minimum, because insulin resistance can precede an abnormal A1C by years. Where the pattern is atypical, asymmetric, or progressing unusually fast, we widen the workup rather than assume diabetes and move on.

Interventional and device-based options

The terrain program

Neither device reverses insulin resistance. Reducing the driver that is killing the nerve fiber in the first place is the terrain half of the plan — time-restricted eating, targeted movement that improves microvascular flow without traumatizing already-fragile feet, and the same in-house Acceptance and Commitment Therapy we build into every chronic pain protocol, because the frustration of a numb, unpredictable foot has a behavioral cost of its own. See metabolic health and pain for how that piece is structured.

Where surgery does not fit

Surgery does not treat diabetic peripheral neuropathy. There is no operation that repairs a small fiber damaged by years of hyperinsulinemia and microvascular starvation, and we will tell you that directly rather than let an implant conversation imply otherwise — the stimulator devices above are placed surgically, but they modulate the pain signal, they do not reverse the underlying nerve injury. Nerve decompression surgery has a role in a narrower, different diagnosis — a single nerve physically entrapped at a specific site — and that distinction is worth getting right before anyone operates.

Red flags that change the visit

• A foot ulcer, wound, or area of skin breakdown — needs same-day wound care evaluation regardless of pain level, because numbness hides infection until it is advanced.
• Rapid, asymmetric onset over days rather than months — points away from typical diabetic neuropathy and toward a cause that needs faster workup.
• Weakness, not just numbness — a motor component changes the differential and the urgency.
• New falls or a sudden change in balance — warrants evaluation before the next fall causes a fracture. See when it is an emergency.

Common questions

Related reading

• Peripheral nerve stimulation
• Spinal cord stimulation
• Metabolic health and pain
• Complex regional pain syndrome
• Opioid stewardship