Bell's palsy is a nonspecific inflammatory reaction, primarily caused by impairment of the facial nerve leading to paralysis of the facial muscles. In general, if the symptoms of Bell's palsy are mild, such as slight drooping of the corner of the mouth and drooling, there is a possibility for spontaneous recovery. However, if the symptoms of Bell's palsy are severe, and the patient also has risk factors for diabetes, these symptoms mainly include noticeably shallower forehead wrinkles, weakness in opening and closing the eyes, inability to close the eyes while sleeping, and very severe facial paralysis. In such cases, spontaneous recovery is difficult, and active treatment is required. Treatment mainly includes corticosteroid drugs and B vitamins, along with some rehabilitative training. In summary, Bell's palsy can resolve on its own if the symptoms are mild; however, if the symptoms are severe, timely treatment is necessary to avoid lasting effects.