Bell's palsy is also known as `acute facial palsy of unknown cause.` It’s a condition in which the muscles on one side of your face become weak or paralyzed. It affects only one side of the face at a time, causing it to droop or become stiff on that side.
Researchers have long believed that viral infections may also play a role in the development of Bell’s palsy. They’ve found evidence that suggests the herpes simplex 1 virus (a common cause of cold sores) may be responsible for a large number of cases. Other viruses that have a link to Bell’s palsy include:
Adenovirus (respiratory conditions)
Coxsackievirus (hand-foot-mouth disease)
Epstein-Barr (infectious mononucleosis)
Herpes zoster (chickenpox and shingles)
Influenza B (flu)
Rubella (German measles)
Besides the weakness and drooping of facial muscles, you may:
Feel pain in your jaw or behind your ear on the side that’s affected. Some people notice pain behind their ear 1 or 2 days before any weakness.
Have a headache
Have less sense of taste
Have dry eyes and mouth
Hear ringing in your ears (tinnitus)
Be more sensitive to sound on the side that’s affected. Sounds seem much louder than normal in the days before you see any other symptoms.
Find it hard to talk
Have trouble eating and drinking
There’s no lab test for Bell’s palsy. In fact, doctors usually find out through what they call a diagnosis of exclusion. That means in most cases, they diagnose Bell’s palsy only after ruling out other conditions.
Your doctor will start by doing a complete and careful physical exam. They’ll examine your face and ask you to make different facial expressions to see how your muscles act.
If they suspect Bell’s palsy, they’ll try to close your eyelid on the affected side of your face. If it doesn’t close, it’ll signal that you have something called the Bell phenomenon.
This is when your eye rolls upward and outward when you try to close it. This is usually enough for them to make the diagnosis.
Your doctor will then try to rule out other conditions. They’ll probably test your hearing and sense of balance. If there’s a chance that another condition is at play, your doctor may order an electromyography (EMG) test to measure the electrical activity inside the muscles.
This can tell them if the nerves are definitely damaged and if so, how much. It may also help them predict how fast and fully you’ll recover.
Your doctor may also run an imaging test, such as skull x-rays, an MRI, or a CT scan, to make sure something like a tumor or bone fracture isn’t pressing on your nerves. A blood test can also help rule out diabetes or an infection.
Most people with this condition make a full recovery whether they get treatment or not. But there are some treatments that may help you heal faster.
Your doctor may give you a short course of corticosteroids (like prednisone). These can help ease swelling and make it more likely that your nerve function will get back to normal. This may shorten the duration of your Bell’s palsy symptoms. They work best if you take them within 72 hours of the start of your symptoms.
If your doctor suggests that your symptoms might be triggered by the herpes virus (herpes simplex 1) or by shingles (herpes zoster), they may give you an antiviral medication. Taking an antiviral like acyclovir and valacyclovir along with the steroids may help restore function, but there isn’t definite proof of this.
If your palsy affects your ability to blink and close your affected eye, you’ll need to protect it. Use eye drops or an ointment to keep it moist. Wear an eye patch to keep dirt and dust out and moisture in.
Finally, your doctor may suggest massage of your facial muscles.
Surgery isn’t recommended as a first treatment option for Bell’s palsy. But you might need it if your symptoms don’t go away or if you have complications.