What is Bell palsy?

Bell palsy is paralysis of the muscles on one side of the face (see drawing). It usually develops over one to three days, and then slowly improves or completely goes away in one to three months. Most people with Bell palsy recover completely, but some are left with weakness on one side of the face.

In about one-fourth of people who have Bell palsy, the affected nerves regrow incorrectly. This can cause your facial muscles to contract (move) on their own.

Bell palsy is most common in adults in their 40s, but it can happen at any age.

What causes Bell palsy?

It is caused by swelling of the facial nerve. The exact cause of the swelling is not known.

The facial nerve controls muscles on the side of the face, the flow of tears, and the ability to taste. There are two facial nerves, one on each side. Bell palsy only affects one of them.

Other diseases can affect the facial nerve or cause facial weakness, but these diseases usually have other symptoms that don't happen with Bell palsy.

How is Bell palsy treated?

Treatment usually includes a steroid pill (such as prednisone) and an antiviral pill. You will usually take these for one to two weeks. If you start taking medicines within three days of the start of your symptoms, the chances of complete recovery are better.

Physical therapy may be helpful for people with severe or ongoing facial weakness.

Talk to your doctor about what treatments will work for you.

Where can I get more information?

• Your doctor

• MedlinePlus

  https://medlineplus.gov/bellspalsy.html