Bell's Palsy | 面瘫

Bell’s palsy is a condition that causes temporary facial paralysis (palsy). It usually only affects the muscles on one side of your face. You may have a lopsided smile or an eyelid that you can’t fully close. It rarely affects both sides of your face.

Bell’s palsy happens when there’s inflammation and swelling of your seventh cranial nerve — the nerve that controls facial muscles. Certain conditions (like viral infections) can cause inflammation, but many cases of Bell’s palsy have no clear cause (idiopathic).

Bell’s palsy can affect anyone at any age. But it’s most likely to affect people between the ages of 15 and 60. The average age of onset is 40 years.

The condition gets its name from Sir Charles Bell, a Scottish surgeon who first described it during the 19th century.

Is Bell’s palsy a serious condition?

Bell’s palsy isn’t a serious condition. Most cases go away on their own with time. However, the symptoms of Bell’s palsy are similar to those of serious medical conditions, like a stroke. This is why it’s important to see a healthcare provider as soon as you notice muscle weakness in your face.

Signs of a stroke include:

• One-sided weakness or paralysis.
• Aphasia (difficulty with or loss of speaking ability).
• Loss of muscle control on one side of your face.
• Sudden loss — either partial or total — of one or more senses (vision, hearing, smell, taste and touch).
• Blurred or double vision (diplopia).
• Loss of coordination or clumsiness (ataxia).
• Dizziness.
• Nausea and vomiting.
• Neck stiffness.
• Emotional instability and personality changes.
• Seizures.
• Memory loss (amnesia).
• Headaches (usually sudden and severe).

A stroke is a life-threatening emergency condition where every second counts. If you or someone with you has symptoms of a stroke, IMMEDIATELY call 911 (or your local emergency services number).

How common is Bell’s palsy?

Bell’s palsy is relatively common. About 15 to 30 people out of 100,000 develop it every year. About 1 in 60 people will get it at some point in their life. It’s the most common cause of one-sided facial paralysis.

The main sign of Bell’s palsy is facial muscle paralysis — usually on one side of your face. It looks like one side of your face is drooping. This includes your:

• Forehead.
• Eyebrow.
• Eye and eyelid.
• Corner of your mouth.

Symptoms of Bell’s palsy tend to come on suddenly and reach peak severity within 48 to 72 hours. Some people develop mild facial muscle weakness. Others experience total muscle paralysis in their face.

It’s difficult to make full expressions with Bell’s palsy. Wrinkling your forehead, blinking and grimacing may be difficult or impossible on the affected side. Your face may feel numb or heavy. But you can still feel touch and temperatures (like heat and coolness) on the affected side of your face.

Other symptoms of Bell’s palsy may include:

• Drooling.
• Dry eyes.
• Difficulty speaking, eating or drinking.
• Facial or ear pain.
• Headache.
• Loss of taste.
• Ringing in your ears (tinnitus).
• Sensitivity to sounds (hyperacusis).

Are there warning signs of Bell’s palsy?

Early symptoms of Bell’s palsy — or warning signs — may include a slight fever and pain behind your ear. However, there’s nothing you can do to stop Bell’s palsy from developing once it begins. In addition, you could have these symptoms for another reason and not develop Bell’s palsy.

Having the following may increase your risk of getting Bell’s palsy:

• Diabetes.
• Pregnancy.
• Preeclampsia.
• Obesity (BMI of 30 or higher).
• High blood pressure (hypertension).
• Having had Bell’s palsy before.