Medically reviewed by Drugs.com. Last updated on May 4, 2022.
Bell's palsy is a condition that causes sudden weakness in the muscles on one side of the face. In most cases, the weakness is temporary and significantly improves over weeks. The weakness makes half of the face appear to droop. Smiles are one-sided, and the eye on the affected side resists closing.
Bell's palsy is also known as acute peripheral facial palsy of unknown cause. It can occur at any age. The exact cause is unknown. Experts think it's caused by swelling and inflammation of the nerve that controls the muscles on one side of the face. It could be caused by a reaction that occurs after a viral infection.
Symptoms usually start to improve within a few weeks, with complete recovery in about six months. A small number of people continue to have some Bell's palsy symptoms for life. Rarely, Bell's palsy occurs more than once.
Signs and symptoms of Bell's palsy come on suddenly and may include:
- Rapid onset of mild weakness to total paralysis on one side of your face — occurring within hours to days
- Facial droop and difficulty making facial expressions, such as closing your eye or smiling
- Pain around the jaw or in or behind your ear on the affected side
- Increased sensitivity to sound on the affected side
- A loss of taste
- Changes in the amount of tears and saliva you produce
In rare cases, Bell's palsy can affect the nerves on both sides of your face.
When to see a doctor
Seek medical help right away if you experience any type of paralysis because you may be having a stroke. Bell's palsy is not caused by a stroke, but it can cause similar symptoms.
If you have facial weakness or drooping, see your health care provider if you have facial weakness or drooping to find out the underlying cause and severity of the illness.
The nerve that controls your facial muscles passes through a narrow corridor of bone on its way to your face. Facial weakness or paralysis may cause one corner of your mouth to droop, and you may have trouble retaining saliva on that side of your mouth. The condition may also make it difficult to close the eye on the affected side of your face.
Although the exact reason Bell's palsy occurs isn't clear, it's often related to having a viral infection. Viruses that have been linked to Bell's palsy include viruses that cause:
- Cold sores and genital herpes (herpes simplex)
- Chickenpox and shingles (herpes zoster)
- Infectious mononucleosis (Epstein-Barr)
- Cytomegalovirus infections
- Respiratory illnesses (adenovirus)
- German measles (rubella)
- Mumps (mumps virus)
- Flu (influenza B)
- Hand-foot-and-mouth disease (coxsackievirus)
The nerve that controls facial muscles passes through a narrow corridor of bone on its way to the face. In Bell's palsy, that nerve becomes inflamed and swollen — usually related to a viral infection. Besides facial muscles, the nerve affects tears, saliva, taste and a small bone in the middle of the ear.
Bell's palsy occurs more often in people who:
- Are pregnant, especially during the third trimester, or who are in the first week after giving birth
- Have an upper respiratory infection, such as the flu or a cold
- Have diabetes
- Have high blood pressure
- Have obesity
Recurrent attacks of Bell's palsy are rare. But when they do recur, there's often a family history of recurrent attacks. This suggests that Bell's palsy might have something to do with your genes.
A mild case of Bell's palsy typically disappears within a month. Recovery from a more severe case where the face was completely paralyzed can vary. Complications may include:
- Irreversible damage to your facial nerve.
- Irregular regrowth of nerve fibers. This may result in involuntary contraction of certain muscles when you're trying to move other muscles (synkinesis). For example, when you smile, the eye on the affected side may close.
- Partial or complete blindness of the eye that won't close. This is caused by excessive dryness and scratching of the clear protective covering of the eye (cornea).
There's no specific test for Bell's palsy. Your health care provider will look at your face and ask you to move your facial muscles by closing your eyes, lifting your brow, showing your teeth and frowning, among other movements.
Other conditions — such as a stroke, infections, Lyme disease, inflammatory conditions and tumors — can cause facial muscle weakness that mimics Bell's palsy. If the cause of your symptoms isn't clear, your health care provider may recommend other tests, including:
- Electromyography (EMG). This test can confirm the presence of nerve damage and determine its severity. An EMG measures the electrical activity of a muscle in response to stimulation. It also measures the nature and speed of the conduction of electrical impulses along a nerve.
- Imaging scans. Magnetic resonance imaging (MRI) or computerized tomography (CT) may be needed on occasion to rule out other possible sources of pressure on the facial nerve, such as a tumor or skull fracture.
- Blood tests. There is no blood test for Bell's palsy. But blood tests can be used to rule out Lyme disease and other infections.
Most people with Bell's palsy recover fully — with or without treatment. There's no one-size-fits-all treatment for Bell's palsy. But your health care provider may suggest medications or physical therapy to help speed your recovery. Surgery is rarely an option for Bell's palsy.
Because the eye on the affected side doesn't close, it's important to take steps to protect and care for that eye. Using lubricating eye drops during the day and an eye ointment at night will help keep your eye moist. Wearing glasses or goggles during the day and an eye patch at night can protect your eye from getting poked or scratched. In severe cases of Bell's palsy, an eye doctor may need to monitor the eye.
Commonly used medications to treat Bell's palsy include:
- Corticosteroids, such as prednisone. These are powerful anti-inflammatory agents. If they can reduce the swelling of the facial nerve, the nerve will fit more comfortably within the bony corridor that surrounds it. Corticosteroids may work best if they're started within several days of when your symptoms started. Steroids started early improve the likelihood of complete recovery.
Antiviral drugs. The role of antivirals remains unsettled. Antivirals alone have shown no benefit compared with placebo. Antivirals added to steroids may benefit some people with Bell's palsy, but this is still unproved.
Despite this, an antiviral drug, such as valacyclovir (Valtrex) or acyclovir (Zovirax), is sometimes given in combination with prednisone in people with severe facial palsy.
Paralyzed muscles can shrink and shorten, which may be permanent. A physical therapist can teach you how to massage and exercise your facial muscles to help prevent this from occurring.
In the past, decompression surgery was used to relieve the pressure on the facial nerve by opening the bony passage that the nerve passes through. Today, decompression surgery isn't recommended. Facial nerve injury and permanent hearing loss are possible risks associated with this surgery.
Rarely, plastic surgery may be needed to correct lasting facial nerve problems. Facial reanimation surgery helps make the face look more even and may restore facial movement. Examples of this type of surgery include an eyebrow lift, an eyelid lift, facial implants and nerve grafts. Some procedures, such as an eyebrow lift, may need to be repeated after several years.
Lifestyle and home remedies
Home treatment may include:
- Taking pain relievers. Aspirin, ibuprofen (Advil, Motrin IB, others) or acetaminophen (Tylenol, others) are available without a prescription and may help ease your pain.
- Doing physical therapy exercises. Massaging and exercising your face according to your physical therapist's advice may help relax your facial muscles.
Although there's little scientific evidence to support the use of alternative medicine for people with Bell's palsy, some people with the condition may benefit from the following:
- Acupuncture. Placing thin needles into a specific point in your skin helps stimulate nerves and muscles, which may offer some relief.
- Biofeedback training. By teaching you to use your thoughts to control your body, biofeedback training may help you gain better control over your facial muscles.
- Botulinum toxin. This medication may help manage symptoms such as facial spasms and tearing. Injections of botulinum toxin may also help improve symmetry of the face.
Preparing for an appointment
You'll likely start by seeing your family doctor or other health care provider. However, in some cases when you call to set up an appointment, you may be referred immediately to a doctor who specializes in the nervous system (neurologist).
It's good to prepare for your appointment. Here's some information to help you get ready.
What you can do
- Write down any symptoms you're experiencing. Be sure to include any that may seem unrelated to the reason for which you scheduled the appointment.
- Write down key personal information. Have you had any major stresses or life changes recently? Sharing this type of information may help with a diagnosis.
- Make a list of all medications. Include the dosage of any medications you're taking. Write down any vitamins or supplements that you're taking, too.
- Take a family member or friend along, if possible. Sometimes it can be difficult to remember all of the information during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- Write down questions you want to ask.
Preparing a list of questions will help you make the most of your time with your provider. For Bell's palsy, some basic questions to ask include:
- What's the most likely cause of my symptoms?
- Are there any other possible causes for my symptoms?
- What kinds of tests do I need?
- Is this condition likely temporary or long lasting?
- What treatments are available for Bell's palsy? Which do you recommend?
- Are there alternatives to the primary approach that you're suggesting?
- I have other health conditions. How can I best manage these conditions together?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend?
Don't hesitate to ask any additional questions that occur to you during your appointment.
What to expect from your doctor
Be prepared to answer questions such as:
- When did you begin having symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
- Have any of your relatives ever had Bell's palsy or problems with facial paralysis?
- Have you had any symptoms of a more generalized infection?
What you can do in the meantime
If you have facial pain:
- Take pain relievers. Aspirin, ibuprofen (Advil, Motrin IB, others) or acetaminophen (Tylenol, others) can help with pain.
- Apply moist heat. Putting a washcloth soaked in warm water on your face several times a day may help relieve pain.
If your eye won't close completely, try these tips:
- Use your finger to close your eye repeatedly throughout the day.
- Use lubricating eye drops.
- Wear eyeglasses during the day to protect your eye.
- Wear an eye patch at night.