Definition of Bell's palsy:

Bell's palsy is a temporary form of facial paralysis that occurs with damage to the nerve that controls movement of the muscles in the face.

Causes, incidence, and risk factors:

Bell's palsy is a form of cranial mononeuropathy VII. It is the most common type of this nerve damage. Bell's palsy affects about 2 in 10,000 people.

Bell's palsy involves damage to the seventh cranial (facial) nerve. This nerve controls the movement of the muscles of the face. The cause is often not clear, although herpes infections may be involved.

Bell's palsy is thought to be linked to swelling (inflammation) of the nerve in the area where it travels through the bones of the skull. Other conditions related to Bell's palsy include:

• Diabetes
• Lyme disease
• Sarcoidosis