How is Bell's palsy diagnosed?
Because the symptoms of Bell's palsy are similar to a number of other conditions that can cause sudden weakness in the facial muscles, part of diagnosing Bell's is to rule out these conditions. These condition include stroke, Lyme disease and head or skull injury. If the cause of the facial weakness is not clear, further tests may be required. These include electromyography (a test to identify nerve damage), blood tests, and imaging scans to identify problems such as a stroke or tumour.