Numbness and Tingling: Common Causes and When to Be Seen

What it involves

MedlinePlus describes numbness and tingling as abnormal sensations that can occur anywhere in the body, but are often felt in the fingers, hands, feet, arms, or legs. They are a symptom, not a diagnosis, and the cause can be as simple as sitting in one position or as important as a nerve, vitamin, or blood sugar problem.

Who this is for

• Adults with numbness or tingling that has no obvious cause like a foot falling asleep
• Patients with diabetes or a thyroid problem who notice new tingling in the hands or feet
• Patients with neck or low back pain that now travels down an arm or leg
• Patients who want to know which symptoms mean calling 911 instead of booking a visit

What to expect

• Questions about where the feeling is, when it began, and what makes it better or worse
• An exam that includes a careful check of the nervous system
• Questions about your medicines, work habits, and risk for diabetes, thyroid disease, or stroke
• A plan that may include blood tests, a change in medicines, or a referral for nerve testing or imaging

Everyday causes

MedlinePlus lists simple causes first: sitting or standing in the same position for a long time, and pressure on a nerve from sitting with the legs crossed. It also explains that a nerve injury can show up far from the injury, so a neck injury may cause numbness anywhere along the arm or hand, while a low back injury can cause numbness or tingling down the leg or foot. The neck pain evaluation and the low back pain evaluation cover those two sources.

Medical conditions behind it

MedlinePlus says numbness and tingling can be caused by other medical conditions, including:

• Diabetes, and an underactive thyroid
• Carpal tunnel syndrome, which is pressure on the median nerve at the wrist
• Migraines, seizures, multiple sclerosis, stroke, and transient ischemic attack
• Raynaud phenomenon, a narrowing of the blood vessels in the hands and feet
• Pressure on the nerves of the spine, such as from a herniated disk

Vitamins, minerals, and medicines

MedlinePlus also lists a deficiency of B vitamins such as B1, B6, B12, or folic acid, abnormal levels of calcium, potassium, or sodium, and nerve damage from alcohol, tobacco, lead, or chemotherapy medicines. Shingles and some other infections are on the list, as are certain medicines. The vitamin D and B12 blood tests guide explains who is usually tested, and the diabetes management page covers the blood sugar side. Do not stop a medicine on your own.

Call 911 or go to the emergency room

MedlinePlus says to call 911 or go to a hospital if numbness or tingling comes with any of these:

• Weakness, or being unable to move
• A recent head, neck, or back injury
• Loss of control of an arm or leg, or of bladder or bowel control
• Confusion or loss of consciousness, even briefly
• Slurred speech, a change in vision, or difficulty walking

Reasons to book a visit

MedlinePlus says to contact your provider if the numbness or tingling has no obvious cause, if you have pain in the neck, forearm, or fingers, or if it is in your legs and gets worse when you walk. It also lists urinating more often, a rash, dizziness, muscle spasm, or other unusual symptoms. A visit is the right step for anything that keeps coming back, because the cause decides the treatment. Numbness or tingling that runs from the lower back down one leg may be sciatica, which the sciatica guide describes along with the red-flag symptoms.

What a visit involves

MedlinePlus says your provider takes a history and examines the nervous system, asking about symptoms, work habits, medicines, and your risk for stroke, thyroid disease, or diabetes. Blood tests it lists include a complete blood count, glucose, electrolytes and liver function, thyroid function, and vitamin levels, particularly B12. The basic metabolic panel guide and the thyroid blood tests guide explain two of them. Nerve studies and imaging would be arranged through a referral. Burning or tingling on one side of the body before any rash appears can be an early sign of shingles, as described in the shingles guide.

Treatment follows the cause

MedlinePlus says treating the cause may make the symptoms go away or stop them from getting worse. Low vitamin levels are treated with supplements, and medicines that cause the problem may need to be switched, but it warns not to change or stop medicines or take large doses of vitamins until you have talked with your provider. Because numbness lowers feeling, it advises protecting a numb hand or foot from cuts, bumps, and burns.

Sources

• MedlinePlus — Numbness and tingling