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.

Palin noted doctors said her facial paralysis could have been brought on by “a case of Bell’s palsy" due to "stress or lack of sleep"