Bell’s palsy

Alternative Names

Facial palsy; Idiopathic peripheral facial palsy; Cranial mononeuropathy

Definition of Bell’s palsy

Bell’s palsy is a disorder of the nerve that controls movement of the muscles in the face.

Causes, incidence, and risk factors

Bell’s palsy affects about 30,000 – 40,000 people a year in the United States.


Sometimes you may have a cold shortly before the symptoms of Bell’s palsy begin.

Signs and tests

Often, Bell’s palsy can be diagnosed just by taking a health history and doing a complete physical exam.


Often, no treatment is needed. Symptoms often begin to improve right away. However, it may take weeks or even months for the muscles to get stronger, and this may be frustrating.

Expectations (prognosis)

Most cases go away completely within a few weeks to months.


David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Luc Jasmin, MD, PhD, Department of Anatomy, Cedars Sinai Medical Center, Los Angeles, and Department of Anatomy, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 7/12/2010

Ptosis, drooping of the eyelid
Facial drooping

ADAM Medical Encyclopedia

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