The majority of patients begin to develop symptoms gradually and manifests completely by 48 hours after onset. The first symptoms include unusual sensations on the affected side of the face, around the ear, changes in audition and taste. As the facial paralysis progresses, difficulty closing the mouth and eyes and keeping food in the mouth develops.

Medical professionals usually diagnose facial paralysis on the basis of the physical medical exam. Examination of the facial muscles will reveal weakening in muscles contraction. Assessment of all cranial nerves can help narrow the location and cause of facial nerve inflammation.

If no other symptoms o signs of any other underlying problems exist, your doctor may diagnose facial paralysis without other diagnostic exams. It may be helpful to order blood glucose levels if the patient is diabetic or has a family history of diabetes.