What Is Bell's Palsy?

Bell's palsy is a temporary weakness or paralysis of the muscles on one side of the face. These muscles are controlled by the facial nerve. Because there's a facial nerve on each side of a person's face, and Bell's palsy usually affects just one nerve, people with Bell's palsy will most likely notice stiffness or weakness on one side of the face.

When the facial nerve is working properly, it carries a host of messages from the brain to the face. These messages may tell an eyelid to close, one side of the mouth to smile or frown, or salivary glands to make spit. Facial nerves also help our bodies make tears and taste favorite foods.

But if the nerve swells and is compressed, as happens with Bell's palsy, these messages don't get sent correctly. The result is weakness or temporary paralysis of the muscles on one side of the face.

What Causes It?

Bell's palsy is most often connected with a viral infection such as herpes (the virus that causes cold sores), Epstein-Barr (the virus that causes mono), or influenza (the flu). It's also associated with the infectious agent that causes Lyme disease. Of course, this doesn't mean that everyone who has a viral infection or Lyme disease will develop Bell's palsy — most people don't.

But in a few people, the immune system's response to a viral infection leads to inflammation of the nerve. Because it's swollen, the nerve gets compressed as it passes through a small hole at the base of the skull, which causes the symptoms of Bell's palsy.

Bell's palsy can affect people of all ages, but it is most common in adults. People with diabetes and pregnant women are more likely to develop Bell's palsy.

What Are the Signs and Symptoms?

The symptoms of Bell's palsy usually show up about 1 to 2 weeks after a viral infection. The symptoms tend to come on quickly — usually Bell's palsy reaches its worst point within 48 hours. A few hours or days before Bell's palsy develops fully, some people may have a headache or feel pain behind or in front of their ears. A person may notice one side of his or her face droops or feels stiff. Some people may only notice a slight weakness, whereas others may not be able to move that side of their face at all.

Other symptoms of Bell's palsy include:

• difficulty closing one eye all the way
• dryness in one eye
• trouble tasting at the front of the tongue on the affected side
• changes in the amount of saliva or drooling
• hearing sounds that seem louder than usual in one ear

Bell's palsy affects only the face, so if a person has weakness or symptoms in other parts of the body, the problem has another cause.

How Is It Diagnosed?

If you have any of the symptoms of Bell's palsy, you should see a doctor as soon as possible.

The doctor will take a detailed medical history and perform a thorough exam to eliminate other possible causes of your symptoms. The doctor will want to know over what period of time your symptoms developed, if you had any preceding illness or trauma, and if you are noticing any other problems such as weakness or paralysis in other parts of your body.

Tell the doctor if you are having problems like double vision or trouble swallowing or if you recently injured your face or head. Because more serious conditions than Bell's palsy, such as an injury, can cause facial paralysis, it's important to report any other problems you may be noticing.

There isn't a specific test for Bell's palsy, although a doctor may test for Lyme disease, herpes virus (HSV), or other infection. Some infections, like Lyme, can be treated, but in most cases the virus that may have caused Bell's palsy in the first place has usually passed.

If the doctor suspects some other cause for a person's symptoms, he or she may use imaging tests, such as X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI), to look inside the body and check for other problems. Some doctors may recommend an electromyography (EMG), which tests how well the muscles respond to nerve signals.

How Is It Treated?

For the symptoms of Bell's palsy to improve, the nerve needs to renew itself, and that can only happen with time. However, some doctors may prescribe medicine to reduce inflammation. If a person with Bell's palsy is unable to close one eye completely, the doctor may prescribe eye drops, an eye patch, and protective glasses to make a person feel more comfortable and to prevent damage to the cornea.

Although it can seem frightening at first, most people with Bell's palsy recover fully within 1 to 3 months. A few people are left with some permanent facial weakness after recovering from Bell's palsy, though.

Taking Care of Yourself

It's important to eat well and get lots of sleep when you have Bell's palsy. Good nutrition and rest will help your body as it heals itself.

One of the hardest things about having Bell's palsy can be dealing with the emotions that go with it. To begin with, Bell's palsy can be just plain scary. And because Bell's palsy affects how your face looks for a while, you may feel self-conscious or embarrassed in public. Even your close friends may tease you in what they think is a good-natured way, but if it feels hurtful to you, tell them. Let people know why your face looks the way it does. Bell's palsy isn't contagious, so no one can catch it from you, and nothing you or anyone else did caused it to happen.

Dealing with a condition like Bell's palsy often helps you find out who your friends really are. Rely on the people you know can offer you the best support — your closest friends, family, or a school counselor, for example. Within a couple of months, you should be back to your old self.

Reviewed by: Mena T. Scavina, MD
Date reviewed: May 2012