Bell’s palsy, also called idiopathic facial paralysis, is an inexplicable condition of facial muscle weakness or paralysis. In other words, Bell’s palsy is sudden muscle weakness in the middle of the face. It starts suddenly and gets worse within 48 hours. This condition is caused by damage to the facial nerve (seventh cranial nerve). Pain and discomfort usually occur on one side. Bell’s palsy can affect people of any age. Bell’s palsy may be a response to a viral infection and rarely occurs more than once. It is characterized by muscle weakness, leading to sagging half of the face.