specific cause of Bell's palsy is unknown, however, it has been suggested that the disorder is due to inflammation that is directed by the body's immune system against the nerve controlling movement of the face. The weakness or symptoms seen in Bell's palsy is sometimes associated with the following: Diabetes High blood pressure Trauma Toxins Lyme disease Guillain-Barré syndrome Sarcoidosis Myasthenia gravis Infection, especially following a viral infection with Herpes simplex virus (a virus that is related to the cause of the common "cold sores" of the mouth)..consult physician for further details