Bell's palsy has been linked to stress, although a precise cause has not been found. Conditions such as hypertension (high blood pressure), diabetes, Lyme disease and autoimmune disorders, chronic ear infections, tumors and trauma to the head or face have also been identified as coinciding with the illness.

Bristol Palin has shared that she's been experiencing face paralysis affecting the left side of her face over the past week and doctors have said it could be attributed to 'a case of Bell’s palsy' brought on by 'stress or lack of sleep.