In addition to Bell's palsy, a number of other conditions can also cause facial paralysis. Your doctor should be able to determine whether you have Bell's palsy based on the specifics of your symptoms.
For instance, after a stroke the muscles of the forehead and eyelid are rarely affected. Stroke patients are often unable to move their facial muscles voluntarily, but will have facial muscle movements as involuntary emotional responses (as in smiling or laughing). If you have Bell's palsy, however, all facial movements will be paralyzed.
In the case of a tumor, any facial paralysis will usually come on gradually and, depending on the location of the tumor, there may be other symptoms that are not found in Bell's palsy. Most other conditions that can cause facial paralysis include symptoms that are not common to Bell's palsy.
What Are the Symptoms of Bell's Palsy?
The symptoms of Bell's palsy can include:
Drooping of the muscles on one side of the face
Inability to close the eyelid on the affected side, including the inability to blink