Bell's palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or 7th cranial nerve.
Damage to this nerve causes weakness or paralysis of these muscles. Paralysis means that you cannot use the muscles at all.
Facial palsy; Idiopathic peripheral facial palsy; Cranial mononeuropathy
Bell's palsy affects about 30,000 - 40,000 people a year in the United States.
Bell's palsy involves damage to the seventh cranial (facial) nerve. This nerve controls the movement of the muscles of the face.
Bell's palsy is thought to be due to swelling (inflammation) of this nerve in the area where it travels through the bones of the skull.
The cause is often not clear. A type of herpes infection called herpes zoster might be involved. Other conditions that may cause Bell's palsy include:
Sometimes you may have a cold shortly before the symptoms of Bell's palsy begin.
Symptoms most often start suddenly, but may take 2 - 3 days to show up. They do not become more severe after that.
Symptoms are almost always on one side of the face only. They may range from mild to severe.
The face will feel stiff or pulled to one side, and may look different. Other symptoms can include:
Other symptoms that may occur:
Often, Bell's palsy can be diagnosed just by taking a health history and doing a complete physical exam.
If your health care provider is worried that a brain tumor is causing your symptoms, you may need:
Sometimes, you will need a test to check the nerves that supply the muscles of your face:
Often, no treatment is needed. Symptoms often begin to improve right away. However, it may take weeks or even months for the muscles to get stronger, and this may be frustrating.
Your health care provider may give you lubricating eye drops or eye ointments to keep the surface of the eye moist if you cannot close it completely. You may need to wear an eye patch while you sleep.
Sometimes medicines may be used, but it is not clear how much they help. If medicines are used, they should be started right away.
Surgery to relieve pressure on the nerve (decompression surgery) has not been shown to benefit most people with Bell's palsy.
Most cases go away completely within a few weeks to months.
If you did not lose all of your nerve function and symptoms began to improve within 3 weeks, you're more likely to regain all or most of the strength in your facial muscles.
Sometimes, the following symptoms still may be present:
Excess drying of the eye surface, leading to eye sores or infections.
Call your health care provider right away if your face droops or you have other symptoms of Bell's palsy. Your health care provider can rule out other, more serious conditions, such as stroke.
There is no known way to prevent Bell's palsy.
de Almeida JR, Al Khabori M, Guyatt GH, Witterick IJ, Lin VY, Nedzelski JM, et al. Combined corticosteroid and antiviral treatment for Bell palsy: a systematic review and meta-analysis. JAMA. 2009;302:985-993.
McAllister K, Walker D, Donnan PT, Swan I. Surgical interventions for the early management of Bell's palsy. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD007468.