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Quick Facts

Bell Palsy


The Manual's Editorial Staff

Last full review/revision Jul 2021| Content last modified Jul 2021
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What is Bell palsy?

Bell palsy is sudden weakness on one side of your face. It happens when a nerve in your face (called the facial nerve) swells and gets squeezed.

  • Bell palsy affects only one side of your face

  • That side of your face becomes weak and droops

  • Treatment usually involves medicine called corticosteroids

  • Most people with Bell palsy get better within several months, even without treatment

What causes Bell palsy?

Doctors don’t always know what causes Bell palsy. An infection may cause the nerve to swell. In some cases, it’s caused by a virus like those that cause shingles, cold sores, mono, or the flu.

What are the symptoms of Bell palsy?

Symptoms start suddenly, usually within hours. Within 48 to 72 hours, your symptoms are as bad as they’ll get.

Bell palsy weakens the muscles on one side of your face. Sometimes you have a little pain behind your ear before the weakness starts. The weakness may range from mild weakness to a total inability to move, called paralysis. On your weak side, you may have:

  • A hard time making an expression, such as wrinkling your forehead, blinking, or smiling

  • Numbness or a heavy feeling

  • Trouble closing your eye, causing it to become dry

  • Dry mouth or drooling

  • Trouble tasting with the front part of your tongue

  • Hearing that makes sounds seem louder than usual

Your facial nerve may not always heal the right way. This can cause unusual face movements or watery eyes. Sometimes, your facial muscles may stay tight.

How can doctors tell if I have Bell palsy?

The doctor will examine you to diagnose Bell palsy. There's no specific test for Bell palsy. To confirm your symptoms aren't caused by something else, your doctor may do tests:

How do doctors treat Bell palsy?

  • Most people who have Bell palsy recover completely, without treatment, in several months

  • Some people who have severe Bell palsy and can't move one side of their face at all may not recover fully

  • If you’ve had symptoms for less than 48 hours, doctors may give you medicine called a corticosteroid that can make full recovery even more likely

  • If you cannot close your eye all the way, your doctor may give you eye drops or a patch to protect your eye from drying out too much

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