Bell’s palsy is a neurological condition that results in facial weakness or paralysis. This disorder occurs when the facial nerve, which controls the muscles of the face, becomes inflamed. While the cause has not been definitively proven, this inflammation is thought to be related to a virus.
Bell’s palsy is the leading cause of facial paralysis. The condition is usually temporary; in most cases, it resolves over time without long-term complications. However, up to 30% of patients can have some long-term effects from Bell’s palsy, a condition known as synkinesis.
On this page:
What Is Bell’s Palsy?
Bell’s palsy, also known as idiopathic facial palsy, is a neurological condition that results in weakness or paralysis. It usually affects one side of the face. In rare cases, it may affect both sides of the face.
This disorder arises from inflammation of the seventh cranial nerve, also known as the facial nerve, which connects the brain to the muscles that control facial expressions. This nerve also affects taste and ear sensation.
When this nerve becomes inflamed or impaired, it leads to difficulty with facial movements and expressions. Bell’s palsy is recognized as the leading cause of facial paralysis.
Most cases resolve within a few weeks to a few months. You are more likely to recover to normal facial function if you had a mild case of Bell’s palsy. Mild cases of Bell’s palsy are characterized by incomplete facial paralysis and/or quicker return of function (within a few weeks).
What causes Bell’s palsy?
The exact cause of Bell’s palsy is unknown. Research has shown that symptoms of facial paralysis and weakness are associated with dysfunction of the seventh cranial nerve, which controls the muscles of the face. Some evidence suggests that this dysfunction may be due to inflammation or swelling caused by a viral infection. This can be triggered by impaired immunity resulting from illness, sleep deprivation, stress, or pregnancy.
Recurrent Bell’s palsy episodes are rare, but most cases are in people with a family history of the disorder, implying a genetic connection.
Bell’s palsy risk factors
Anyone can develop Bell’s palsy, but it is more common in adults than in children.
Risk factors and possible triggers for Bell’s palsy include:
Complications of Bell’s palsy
Most symptoms of Bell’s palsy go away on their own with time. However, some people may experience long-term effects from Bell’s palsy, known as synkinesis.
These symptoms may include:
- Difficulty showing feelings through facial expressions.
- Eye dryness leading to infections, sores, and vision loss.
- Facial asymmetry (unevenness).
- Long-term changes in taste.
- Spasms of eyelid muscles.
- Synkinesis (a disorder affecting facial movement).
- Tightness of facial muscles.
- Trouble eating and drinking.
- Trouble speaking clearly.
These challenges can cause people with Bell’s Palsy to suffer emotional distress and depression.
How common is Bell’s palsy?
According to the American Brain Foundation, Bell’s palsy affects approximately 40,000 people in the U.S. each year. The age range with the highest incidence is 15 to 45, with 85% of people experiencing symptom improvement within three weeks of treatment.
What Are the Signs and Symptoms of Bell’s Palsy?
Symptoms of Bell’s palsy usually appear quickly (within one to two days). People typically experience a sudden onset of facial weakness or facial droop. This can be associated with ear pain, changes in taste sensation, and sensitivity to loud noises.
Symptoms may vary from person to person, but most people start to get better after a few weeks. Facial movement often returns within several weeks to six months, although some people develop permanent synkinesis.
The most common symptom of Bell’s palsy is sudden weakness or paralysis on one side of the face.
Other symptoms of Bell’s palsy include:
- Drooling from one side of the mouth.
- Drooping eyebrow on one side of the face.
- Inability to close one eyelid on the affected side.
Other symptoms that may affect people with Bell's palsy include:
- Chewing and swallowing problems.
- Distorted sense of taste.
- Ear pain.
- Excessive tearing in one eye.
- Sensitivity to loud sounds.
When should I see a doctor about my Bell’s palsy symptoms?
It's important to be evaluated promptly if you develop signs or symptoms of Bell’s palsy. Other potential causes of facial paralysis, including stroke or Lyme disease, must be ruled out. A medical evaluation can help ensure no underlying conditions are causing your symptoms and that you receive appropriate treatment.
How Do You Diagnose Bell’s Palsy?
There is no specific lab test to confirm a diagnosis of Bell’s palsy.
Your provider will ask you about your symptoms, including when they started, take your medical history, and perform a physical examination. They will check your upper and lower facial muscles for weakness on one side, including your eyelid, forehead, and mouth, to rule out other possible causes of facial paralysis, such as brain tumor, Lyme disease, myasthenia gravis, and stroke.
Your provider may order routine lab tests to find out if you have an infection or other health problems that could be causing your facial weakness or paralysis. They might also check for signs of nerve trouble or damage.
Tests that might be ordered include:
How Do You Treat Bell’s Palsy?
Bell’s palsy is typically treated with steroids and antiviral medications. Surgery is rarely done to treat Bell’s palsy in the acute setting.
Medicine to treat Bell’s palsy
Doctors often prescribe steroids to people who have just started showing signs of Bell’s palsy. It’s best to begin taking these medicines within three days after symptoms appear because they can help decrease swelling and make it more likely for the facial nerve to recover.
Doctors may also prescribe antiviral drugs, which can help improve your chances of regaining facial movement. You might also try regular painkillers like aspirin, acetaminophen, or ibuprofen.
If you have trouble closing one of your eyelids, especially at night while sleeping, lubricating eye drops and eye patches can help keep the eye moist and protect it from debris or injury.
Other therapies that may help include:
- Acupuncture
- Facial massage
- Physical therapy
Surgery to treat Bell's palsy
Decompression surgery to relieve pressure on the facial nerve has not been shown to benefit most people with Bell’s palsy. In some cases, cosmetic or reconstructive surgery can repair permanent disfigurement from Bell’s palsy, such as a crooked smile. In rare cases, surgery may be needed to protect the eye or improve recovery of facial nerve function.
How effective is treatment?
Most people with Bell’s palsy — about 70% to 80% — will recover completely, even if they don’t get treatment. If medicine is started quickly, over 95% of patients recover fully.
For those who don’t fully recover, their facial muscles can become tight or move in unusual ways. They might need physical therapy, botulinum toxin (Botox) injections, or even surgery to help their face function more normally.
Why Choose UPMC for Bell’s Palsy Care?
For more than 20 years, experts at the UPMC have diagnosed and treated many people suffering from facial nerve disorders, including Bell’s palsy.
As one of the leading centers of expertise in facial paralysis worldwide, we often provide answers and second opinions for patients who feel they've run out of options.
