Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get StartedCauses
By Mayo Clinic staffThe most common cause of Bell's palsy appears to be the herpes simplex virus, which also causes cold sores and genital herpes. Other viruses that have been linked to Bell's palsy include:
- The virus that causes chickenpox and shingles (herpes zoster)
- The virus that causes mononucleosis (Epstein-Barr)
- Another virus in the same family (cytomegalovirus)
With Bell's palsy, the nerve that controls your facial muscles, which passes through a narrow corridor of bone on its way to your face, becomes inflamed and swollen — usually from a viral infection. Besides facial muscles, the nerve affects tears, saliva, taste and a small bone in the middle of your ear.
- Bell's palsy fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/bells/detail_bells.htm. Accessed Nov. 10, 2009.
- Ronthal M. Bell's palsy. http://www.uptodate.com/home/index.html. Accessed Nov. 11, 2009.
- Bell's palsy. American Academy of Otolaryngology — Head and Neck Surgery. http://www.entnet.org/HealthInformation/bellsPalsy.cfm. Accessed Nov. 10, 2009.
- Bell's palsy. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec16/ch219/ch219i.html. Accessed Nov. 11, 2009.
- Cardoso JR, et al. Effects of exercises on Bell's palsy: Systematic review of randomized controlled trials. Ontology & Neurotology. 2008;29:557.
- De Almeida JR, et al. Combined corticosteroid and antiviral treatment for Bell palsy: A systematic review and meta-analysis. Journal of the American Medical Association. 2009;302:985.