Bell's palsy can cause fever, usually a low-grade fever. When the body temperature is between 37°C and 38°C, it is generally referred to as low-grade fever.

The primary cause of Bell's palsy is viral infection. Patients may also exhibit symptoms such as eye fissures, paralysis of the facial expression muscles of the upper and lower face, disappearance of forehead creases, enlargement of the eye fissures, incomplete eyelid closure, showing white sclera when the eyes are closed, shallowing of the nasolabial folds, deviation of the mouth corners, air leakage when whistling, air escaping when puffing cheeks, loss or reduction of taste in the anterior two-thirds of the tongue, and difficulty in retaining food on the affected side when eating. Patients are prone to developing oral inflammation and conjunctivitis. Early and proper treatment after the onset is crucial, and most patients can achieve clinical cure after treatment.