Bell's palsy: excluding serious illness in urgent and emergency care settings.

Bell's palsy is a relatively benign condition that affects about 20 in every 100,000 patients a year, and in most cases the signs and symptoms resolve fully within around six months. The defining characteristic of the condition is a unilateral facial palsy, but this is also apparent in other conditions with a more serious prognosis, including strokes, some viral infections and tumours. This article reviews the literature on recognition of Bell's palsy, examines the underlying pathology, and compares it with other conditions associated with facial palsy. The article critically analyses the evidence and guidelines to identify best practice, and considers areas for improvement. Finally, it discusses how this information can be incorporated into practice, and provides guidance for clinicians on differentiating between conditions in which patients present with facial palsy to ensure they are managed appropriately.