Numbness and tingling in your hands or feet: diabetic neuropathy and other causes

Peripheral neuropathy is nerve damage in the body's longest nerves, the ones running to the feet and hands. Diabetes is the most common cause. High blood sugar over time damages these nerves, and the classic first symptom is numbness and a tingling or burning "pins and needles" feeling in the feet, often worse at night, usually on both sides. The feet and legs are affected first; the hands and arms can follow later.

This symptom deserves urgency for Black readers specifically, for two stacked reasons.

First, the exposure is higher. Diagnosed diabetes is more common among non-Hispanic Black adults (12.1 percent) than among non-Hispanic white adults (6.9 percent), close to a two-to-one gap. More people at risk means more people who should treat numb feet as a warning, not a nuisance.

Second, the stakes are higher. The CDC reports that Black adults with diabetes are 30 percent more likely to have a lower-limb amputation than white adults with diabetes, and that they have the highest amputation rate of any racial or ethnic group. Most lower-limb amputations, about 80 percent, are caused by diabetes complications. The CDC names the reason plainly: "barriers to quality care and potential biases in the medical system may contribute to these higher rates."

The chain that ends in amputation starts with numbness. When neuropathy takes away feeling in the feet, you stop noticing pressure, blisters, and small injuries. Those become sores that do not heal, then infections, then the loss of a toe, foot, or part of the leg. Catching the numbness early, controlling blood sugar, and protecting the feet is how you stay off that path. If you have diabetes or are worried about it, our guide to type 2 diabetes covers the broader picture.

Low vitamin B12 damages nerves and produces the same numbness, tingling, and weakness in the hands and feet that diabetes does. It is frequently misread as diabetic neuropathy, and that matters because B12 deficiency can be arrested with replacement, but the nerve damage it causes cannot be reversed once it sets in.

There is a specific trap for people with diabetes. Long-term use of metformin, one of the most common diabetes medicines, lowers B12 by interfering with how the gut absorbs it. Studies have found B12 deficiency in roughly 30 percent of long-term metformin users, and it can show up as a peripheral neuropathy that looks exactly like the diabetic kind. If you take metformin and have numb or tingling feet, ask for a B12 blood test. It is cheap, it is reversible if caught, and missing it means treating the wrong problem.

Not all numbness is widespread nerve damage. Sometimes a single nerve is squeezed.

Carpal tunnel syndrome is the most common nerve-compression syndrome. The median nerve gets compressed at the wrist, causing numbness, tingling, and burning mainly in the thumb, index, middle, and part of the ring finger. Symptoms are typically worst at night and can wake you from sleep, because many people sleep with the wrist bent. Diabetes is itself a risk factor for carpal tunnel.

Tarsal tunnel syndrome is the foot version, where a nerve is compressed near the ankle, producing numbness and tingling in the sole. A simple pinched nerve, for example from a herniated disc in the back, can also cause numbness that follows a specific path down a leg or arm rather than affecting both sides evenly. The pattern matters: nerve compression usually hits one limb or one nerve's territory, while diabetic neuropathy is usually symmetrical in both feet.

• Underactive thyroid. Severe, long-untreated hypothyroidism can damage peripheral nerves and can also cause fluid retention that presses on nerves, contributing to carpal tunnel. A thyroid blood test rules it in or out.
• Heavy alcohol use. Chronic heavy drinking is a recognized cause of peripheral neuropathy.
• Other conditions. Kidney disease, certain infections such as shingles and Lyme disease, autoimmune conditions, some medications, and physical nerve injuries are all on the list.

The point is not to self-diagnose every possibility. It is to know that "numb feet" has a real differential, and a clinician should work through it rather than assume.

If you have diabetes, daily foot care is the single most direct thing you can do to avoid an amputation, because it catches injuries your numb feet cannot feel.

• Look at your feet every day, tops, soles, and between the toes. Use a mirror or ask someone if you cannot see the soles. You are checking for cuts, blisters, redness, swelling, and color changes.
• Wash and dry your feet daily, and keep skin from cracking. Dryness and cracking can open the door to infection, which can be harder to spot on brown and black skin. Our guide to diabetic skin changes on dark skin covers what to watch for.
• Never go barefoot, and check inside your shoes before putting them on, since a numb foot will not feel a pebble or a seam.
• Get any wound that is not healing, any spreading redness, swelling, or new color change seen by a clinician fast. The CDC's amputation-prevention guidance is explicit about seeking immediate care for these.

Bring this list to your appointment. You are entitled to a real workup, not a brush-off.

• A comprehensive foot exam, at least once a year if you have diabetes, more often if you already have foot problems. The American Diabetes Association recommends this include a 10-gram monofilament test for loss of protective sensation plus at least one more check (pinprick, temperature, vibration with a tuning fork, or ankle reflexes).
• A vitamin B12 blood level, especially if you take metformin.
• A thyroid test (TSH) and a check of blood sugar or A1C if diabetes has not been confirmed.
• If the numbness is one-sided or follows one nerve's path, ask whether nerve-conduction studies or evaluation for nerve compression are warranted.

If you need a clinician who will take your symptoms seriously, you can find a provider through our directory.