Bell's palsy is a weakness or paralysis of a facial nerve. The 2 facial nerves control movement of the muscles of expression on each side of your face. When one of the nerves is weak or paralyzed, that side of the face droops. You may also have trouble closing the eye on that side.
The cause of Bell's palsy is not known. A commonly held theory is that a virus causes the nerve to swell. The nerve is then temporarily squeezed against the bony canal through which it passes as it travels from the brain to the face. When this happens, the nerve can no longer control the facial muscles. The muscles become weak or paralyzed and muscle control is lost.
The first symptom may be an ache behind the ear on the side of your face that is affected. Then that side of your face will become weak or paralyzed. The paralysis usually starts in the lower part of the face. Other possible symptoms are tearing of the eye, decreased taste, a change in hearing, and trouble drinking or chewing. You may slur your words when you talk. The severity of Bell's palsy can vary from a mild weakness to complete paralysis.
Symptoms may develop within a few hours or over a couple of days. The faster the symptoms happen, the more severe the weakness or paralysis is likely to be.
See your healthcare provider right away if your symptoms develop quickly, for example, in 30 to 60 minutes. Your provider will want to make sure that you are not having a stroke. (Strokes need to be treated in the first 3 hours.)
Your healthcare provider will ask about your symptoms and examine you. Your provider will need to rule out other possible causes of your symptoms, such as an injury, stroke, or tumor. You may have a hearing test or brain scan. Electrical testing of the facial nerve may be done to see how much the nerve is damaged.
Your provider may prescribe:
Rarely, when the paralysis is severe, surgery may be done to try to relieve pressure on the nerve.
If the eye on the affected side does not close completely, it needs to be protected from problems such as dust and drying out. This is done by patching the eye or using eyedrops or eye ointments. If the eye is not protected, you could lose vision in that eye.
If you have complete paralysis--that is, no movement of the facial muscles at all--you will probably not have full return of each muscle movement. If you have at least some muscle movement, you have a good chance for a complete recovery.
Even mild cases of Bell's palsy can last several weeks. Complete paralysis may take months to improve as much as it is going to.
Bell's palsy very rarely occurs twice in the same person. If you have facial paralysis again, another problem may be causing it and you should get it checked by your healthcare provider.