Tingling in hands and feet: causes, warning signs and testing

Two main patterns

The pattern of tingling gives important clues. When a single nerve is squeezed, symptoms follow that nerve's territory. Carpal tunnel syndrome, for example, typically affects the thumb, index and middle fingers and is often worse at night or when holding a phone or steering wheel. A pinched nerve in the neck can send tingling down one arm.

Peripheral neuropathy, by contrast, usually begins in the toes and feet on both sides and slowly creeps upward over months. The hands may become involved later. The National Institute of Neurological Disorders and Stroke notes that neuropathy can cause tingling, numbness, burning pain, poor balance and, when motor nerves are involved, weakness.

Common causes after 40

MedlinePlus and NINDS list many causes. The ones most relevant in midlife include:

• Diabetes and prediabetes, including diabetes that has not yet been diagnosed
• Low vitamin B12, which becomes more common with age and with long-term use of metformin or acid-reducing medicines
• Alcohol use
• Underactive thyroid
• Kidney or liver disease
• Carpal tunnel syndrome and pinched nerves in the neck or lower back
• Certain chemotherapy drugs and other medications, and excess vitamin B6 from supplements
• Autoimmune conditions and some infections, such as shingles
• Anxiety with rapid breathing, which can cause temporary tingling around the mouth and in the fingers

When to get help urgently

Some forms of numbness and tingling are emergencies:

• Call 911 for sudden numbness or weakness on one side of the face, arm or leg, trouble speaking, confusion, vision loss, loss of balance or a sudden severe headache
• Go to the emergency room for numbness or weakness that spreads up from the feet over hours or days, trouble walking, loss of bladder or bowel control, or numbness in the groin or buttocks
• Seek urgent care for numbness or tingling right after a head, neck or back injury
• See a clinician promptly for weakness in your grip, wasting of the thumb muscles, persistent tingling on one side, or foot numbness if you have diabetes

What testing can help

Blood tests can identify common, treatable causes: glucose and A1c for diabetes; vitamin B12, sometimes with a follow-up test if the result is borderline; thyroid function; kidney and liver function; and a complete blood count. MedlinePlus also lists electrolytes and inflammation markers among tests that may be ordered.

Blood tests cannot diagnose nerve compression or the type of neuropathy. An in-person neurological exam, and sometimes nerve conduction studies and electromyography (EMG), are used to confirm carpal tunnel syndrome, pinched nerves or neuropathy. Imaging of the neck or spine is used when a pinched nerve is suspected.

Treatment options in general terms

The most important step is treating the cause. Improving blood sugar control can slow diabetic neuropathy, and correcting B12 deficiency can stop progression and sometimes reverse symptoms, especially when caught early. Reducing alcohol, adjusting medications with the prescriber, and treating thyroid or kidney problems also help.

Carpal tunnel syndrome often improves with wrist splints at night and activity changes; steroid injections or surgery are options when symptoms persist. Nerve pain can be treated with certain antidepressants, antiseizure medicines, lidocaine patches or capsaicin cream. People with numb feet should check their feet daily for cuts and blisters.

Why B12 deserves attention

The NIH Office of Dietary Supplements notes that many older adults absorb less B12 from food because of reduced stomach acid, and that metformin and acid-reducing drugs can lower B12 levels. Because the body stores B12, deficiency can develop slowly over years, and nerve damage can occur even without anemia. That makes B12 one of the most worthwhile tests when tingling appears in midlife.

Tracking your symptoms

Before your appointment, note where the tingling is, whether it is on one or both sides, what time of day it is worst, whether it wakes you, and whether shaking out your hand helps. Also list all medications and supplements, including doses of B6, and your alcohol intake.

How HealifyMD can help

A HealifyMD clinician can order labs including A1c, glucose, B12, thyroid, kidney and liver function, review medications that can lower B12, and discuss treatment such as B12 replacement if a deficiency is found. B12 injections through HealifyMD are from $125/month, confirmed at the eligibility review. We do not diagnose neuropathy or nerve compression, so those are referred for an in-person exam and nerve testing.