Numbness and Tingling: Causes to Check Before Buying Any Nerve Supplement

Why the cause matters

Peripheral neuropathy is damage to the nerves outside the brain and spinal cord, and it has more than a hundred known causes ^[1]. The symptoms often look alike: tingling, numbness, burning or pins and needles, usually starting in the toes and feet. What differs is what can be done. Some causes can be halted or reversed once found; a supplement taken without looking for them can delay that.

That is why every honest guide to nerve supplements, including the pages on this site, starts with the same advice: find out why first. Here are the common causes your doctor will usually consider.

Blood sugar

Diabetes is the most common cause of peripheral neuropathy in the United States, and nerve damage can begin in prediabetes. Up to half of people with diabetes develop some form of neuropathy over time ^{[2] [3]}. Long-term high blood sugar damages nerves and the small blood vessels that feed them ^[4].

The relevant tests are fasting glucose and hemoglobin A1C. If you have diabetes, better glucose control is the intervention with the strongest evidence for slowing nerve damage, especially in type 1 diabetes ^[5].

Vitamin B12 and metformin

Vitamin B12 is essential for healthy nerves, and deficiency causes numbness, tingling and balance problems, sometimes before anemia appears ^[6]. Deficiency is more common in older adults, vegans, people who have had stomach surgery, and people on acid-suppressing drugs.

Metformin, the most widely used diabetes drug, lowers B12 absorption over time. In the long-term Diabetes Prevention Program follow-up, metformin use was associated with a higher rate of B12 deficiency, and the risk grew with years of use ^[7]. The American Diabetes Association advises periodic B12 checks in people taking metformin, especially those with neuropathy ^[8]. A blood test answers the question, and treatment is simple.

Thyroid

An underactive thyroid can cause numbness and tingling, partly through fluid that presses on nerves, as in carpal tunnel syndrome ^[9]. Fatigue, weight gain, cold intolerance and dry skin alongside nerve symptoms are reasons to ask for a TSH test.

Alcohol

Heavy, long-term drinking damages nerves directly and through poor nutrition, including low thiamine and other B vitamins ^[1]. Cutting back can stop the progression; it is one of the more controllable causes.

Too much vitamin B6

This one surprises people. Vitamin B6 is in many nerve supplements and multivitamins, and taking too much of it over months can itself cause sensory neuropathy, with numbness and tingling in the hands and feet ^[10]. If you take several supplements, add up the B6 from all of them. NerveHoney contains no B6, but other nerve formulas often do.

Medicines and other causes

Some chemotherapy drugs, certain antibiotics, some HIV medicines and a few heart drugs can cause neuropathy. Kidney disease, autoimmune conditions, infections such as shingles and Lyme disease, and inherited conditions are other causes ^{[1] [11]}. Pressure on a single nerve, as in carpal tunnel syndrome or a pinched nerve in the back, causes symptoms limited to one area and has its own treatments.

Tests to ask about

Your doctor may add others, or a nerve conduction study, depending on what they find. People with diabetes should also have an annual foot exam with simple sensation tests ^{[8] [12]}.

How the doctor's visit usually goes

A first appointment for numbness and tingling is usually short and practical. Expect questions about when the symptoms started, where they are, whether they are spreading, and what makes them better or worse. Expect a list of medicines and supplements to be reviewed, and questions about alcohol and diet.

The examination checks sensation to light touch, pinprick, vibration and temperature, reflexes at the ankles and knees, strength, and balance. A thin nylon filament pressed against the sole, called a monofilament test, is a quick screen for loss of protective sensation, particularly in people with diabetes ^[8]. Blood tests follow, and if the picture is unusual, asymmetric or rapidly changing, a referral for nerve conduction studies or to a neurologist ^[11].

Bringing a short written summary of your symptoms and every product you take makes the visit far more useful.

Questions readers ask about causes

What to do while you wait for results

Tests can take a week or two to come back. In the meantime, a few habits protect you whatever the cause: check your feet every evening for cuts or blisters, wear well-fitting shoes indoors and out, test bath water with your hand or elbow, keep alcohol low, and keep moving with gentle walking if your feet are intact ^[12]. Write down any change in your symptoms, and seek care sooner if weakness or spreading numbness appears. Starting a supplement can wait until you know what you are treating. If a cause turns up, such as low B12 or raised blood sugar, treating it may change your symptoms enough that you never need a nerve supplement at all.

Where a supplement fits

Once the common causes have been checked, and treated where possible, some people still have symptoms and want to try a supplement. That is a reasonable decision, made with the facts. NerveHoney's calming herbs might make evenings easier; they will not correct high blood sugar, low B12 or an underactive thyroid. Read our warning signs guide for symptoms that should not wait, and the review for what the product can and cannot do.