Angelina Jolie developed a condition called Bell’s palsy in 2016, the actress recently told Vanity Fair . What is Bell’s palsy?
Bell’s palsy is a form of temporary facial paralysis, according to the National Institute of Neurological Disorders and Stroke (NINDS). This paralysis usually affects only one side of a person’s face, and so it can make the affected side of the face look like it is drooping. About 40,000 Americans get Bell’s palsy each year, the NINDS says.
The condition is caused by damage to a facial nerve, according to the NINDS. There are two facial nerves, each of which controls the muscles on one side of the face. Which side of the face is affected depends on which nerve is affected.
Scientists don’t know for sure what causes this nerve damage, but they generally think that it’s caused by a viral infection, according to the National Library of Medicine .
When the facial nerve is damaged — for example, it can be swollen, inflamed or compressed — it’s unable to carry messages from the brain to the facial muscles as well as it normally can, which is what leads to the muscle weakness, paralysis or twitching, according to the NINDS. In addition, damage to the nerve can cause the eyelid and the corner of a person’s mouth to droop.