Bell's palsy (MONDO_0005665) is partial or complete paralysis of the facial muscles of one side of a person's face. It is caused by damage to the seventh cranial nerve. It is usually temporary but it may recur. Also known as: Bell palsy, Bell's (facial) palsy, facial nerve palsy, facial nerve paralysis, nerve paralysis, Facial, palsy of facial nerve, paralysis Of Facial nerve.