Bell palsy is an unexplained episode of facial muscle weakness or paralysis that usually goes away on its own and causes no complications.

The cause of Bell palsy is unknown. But it's thought to be caused by inflammation affecting the body’s immune system. It's linked to other conditions, such as diabetes.

Symptoms of facial weakness or paralysis get worse over the first few days and start to improve in about 2 weeks.

It can take 3 to 6 months to fully go away.

Medicine and eye care are important in treating Bell palsy.