Bell's palsy is a paralysis or weakness of the muscles on one side of your face. Damage to the facial nerve that controls muscles on one side of the face causes that side of your face to droop. The nerve may also affect your sense of taste and how you make tears and saliva. This condition comes on suddenly, often overnight, and usually gets better on its own within a few weeks.
Bell's palsy is not the result of a stroke or a transient ischemic attack (TIA). While stroke and TIA can cause facial paralysis, there is no link between Bell's palsy and either of these conditions. But sudden weakness that occurs on one side of your face should be checked by a doctor right away to rule out these more serious causes.
The cause of Bell's palsy is not clear. Most cases are thought to be caused by the herpes virus that causes cold sores.
In most cases of Bell's palsy, the nerve that controls muscles on one side of the face is damaged by inflammation.
Many health problems can cause weakness or paralysis of the face. If a specific reason cannot be found for the weakness, the condition is called Bell's palsy.
Symptoms of Bell's palsy include:
Your doctor may diagnose Bell's palsy by asking you questions, such as about how your symptoms developed. He or she will also give you a physical and neurological exam to check facial nerve function.
If the cause of your symptoms is not clear, you may need other tests, such as blood tests, an MRI, or a CT scan.
Most people who have Bell's palsy recover completely, without treatment, in 1 to 2 months. This is especially true for people who can still partly move their facial muscles. But a small number of people may have permanent muscle weakness or other problems on the affected side of the face.
You may need to take a corticosteroid. This medicine can lower your risk for long-term problems from Bell's palsy. Your doctor may also have you take antiviral medicine, such as acyclovir. Antiviral medicines used alone don't help with Bell's palsy.