Photo by Marina Guimarães

• Share

PRINT

Q: I often wake up with numbness in my hand. After five minutes, it’s back to normal. Why does this happen? When should I worry that something serious is causing it?

A: Since it’s temporary, brief and goes back to normal, it’s probably due to pressure on a nerve near the wrist and unlikely to be due to anything serious.

Numbness and tingling are most commonly due to abnormal nerve function, or, as I like to tell patients, “The nerves are not happy.” 

And when this is intermittent, temporary and related to holding one position for a long time, it’s rarely anything to worry about. 

The cause in these cases is simply pressure on one or more nerves traveling into the hands or feet. When you remove the pressure (by changing position, for example), the problem goes away.

However, there are more than 100 other causes of nerve disease (or neuropathy) that cause similar, though more prolonged and persistent, symptoms. 

An estimated 20 million people have a form of peripheral neuropathy that might make hands or feet feel numb or tingly.

When to see a doctor

If your hands or feet fall asleep occasionally and normal sensation quickly returns, that’s fine. No need to contact your doctor.

But call your doctor promptly if you have persistent numbness, tingling or other unusual sensations in your hands or feet. This is especially important if these sensations cause trouble with walking or holding onto things. 

Your doctor should investigate further and will likely consider possible causes of peripheral neuropathy, including the following:

—Diabetes. This is the most common identifiable cause of peripheral neuropathy, accounting for nearly a third of cases.

—Diseases of the liver, kidney and thyroid

—Nutritional deficits, such as vitamin B12 or other vitamin deficiencies

—Alcohol or exposure to other toxins, such as mercury

—Certain medications, including some chemotherapy drugs or antibiotics

—Vascular disease, which occurs when the blood supply to a peripheral nerve is impaired, as with atherosclerosis

—Compression. Good examples include pressure on a nerve (as described earlier) or carpal tunnel syndrome.

Additional causes of neuropathy are infection, nerve trauma and inflammatory or autoimmune conditions that affect nerves. 

It’s worth noting that nearly a third of cases have no clear cause, a problem known as idiopathic neuropathy.

The causes of peripheral neuropathy are many and range from the harmless and annoying to the intolerable and dangerous. 

When in doubt, see your doctor. But try not to worry when your hands or feet fall asleep due to holding your arms or legs too long in one position, as long as this resolves within minutes and doesn’t happen often. 

For additional consumer health information, visit health.harvard.edu.

© 2020 President and Fellows of Harvard College. All rights reserved. Distributed by Tribune Content Agency, LLC.