DefinitionBy Mayo Clinic Staff
Bell's palsy causes sudden weakness in your facial muscles. This makes half of your face appear to droop. Your smile is one-sided, and your eye on that side resists closing.
Bell's palsy, also known as facial palsy, can occur at any age. The exact cause is unknown, but it's believed to be the result of swelling and inflammation of the nerve that controls the muscles on one side of your face. It may be a reaction that occurs after a viral infection.
For most people, Bell's palsy is temporary. Symptoms usually start to improve within a few weeks, with complete recovery in about six months. A small number of people continue to have some Bell's palsy symptoms for life. Rarely, Bell's palsy can recur.
Dec. 16, 2014
- Bope ET, et al. Conn's Current Therapy. Philadelphia, Pa.: Saunders Elsevier; 2014. http://www.clinicalkey.com. Accessed Nov. 14, 2014.
- Glass GE, et al. Bell's palsy: A summary of current evidence and referral algorithm. Family Practice. In press. Accessed Nov. 14, 2014.
- Ferri FF. Ferri's Clinical Advisor 2015: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2015. https://www.clinicalkey.com. Accessed Nov. 14, 2014.
- Bell's palsy fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/bells/detail_bells.htm. Accessed Nov. 14, 2014.
- Ronthal M. Bell's palsy: Pathogenesis, clinical features, and diagnosis in adults. http://www.uptodate.com/home. Accessed Nov. 15, 2014.
- Ronthal M. Bell's palsy: Prognosis and treatment in adults. http://www.uptodate.com/home. Accessed Nov. 15, 2014.
- Facial nerve palsy. The Merck Manual Professional Edition. http://www.merckmanuals.com/professional/neurologic_disorders/neuro-ophthalmologic_and_cranial_nerve_disorders/facial_nerve_palsy.html?qt=&sc=&alt=. Accessed Nov.16, 2014.
- AskMayoExpert. What is the initial therapy recommended for patients with Bell palsy? Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.