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Bell's palsy

Published by Bupa's health information team, March 2009.

This factsheet is for people who have Bell's palsy, or who would like information about it.

Bell's palsy is a condition in which one side of the face becomes paralysed. It's usually temporary. Symptoms of Bell's palsy generally come on suddenly and have no obvious cause.

About Bell's palsy

Bell's palsy is a condition where the muscles in your face become weak or paralysed. It happens on one side of your face only and is the most common cause of paralysis of the face.

Bell's palsy was named after Sir Charles Bell, a nineteenth-century doctor who first described the condition and linked it to a problem with the facial nerve.

The condition is fairly common. Every year around one in 5,000 people develop Bell's palsy. It can affect people of all age groups, including children, but it's most common in people aged 15 to 45. Men and women are equally affected.

Symptoms of Bell's palsy

The symptoms of Bell's palsy usually come on very quickly - often in a few hours or overnight.

The main symptom is that one side of your face becomes weak or paralysed. You may also find that your eyebrow sags and you find it difficult to close your eye. For some people, mild earache or a pain behind the ear is the first sign of Bell's palsy. You may also find that:

These symptoms aren't always due to Bell's palsy, but if you have them, you should visit your GP for advice.

Around three in four people with Bell's palsy recover completely. Most people see a major improvement within three to eight weeks of developing the condition, but for some people it can take three to six months before symptoms improve, when damaged nerves have had a chance to re-grow. Around one in six people are left with facial weakness, muscle tightness, facial spasms or twitches.

Complications of Bell's palsy

Sometimes, new nerve fibres that grow back after you first developed Bell's palsy join up to the wrong muscles in your face. This can have long-lasting effects, including:

Causes of Bell's palsy

The exact reasons why you may develop Bell's palsy aren't fully understood at present. However, it's thought that a viral infection that affects your facial nerve is the most likely cause. Herpes simplex - the virus responsible for cold sores - has been suggested as responsible for many cases. This virus may lie inactive (dormant) at the root of the facial nerve, causing swelling when it reactivates (wakes up). Ramsay Hunt syndrome is a condition that is similar to Bell's palsy, but here the virus - Varicella zoster (a strain of the herpes virus that causes chicken pox) - has been identified as the cause. Blisters in the ear are often found in Ramsay Hunt syndrome.

You may be more likely to develop Bell's palsy if you have diabetes or are pregnant.

Diagnosis of Bell's palsy

Facial paralysis isn't always the result of Bell's palsy - other causes include:

Your GP will ask you about your symptoms and examine you. He or she may also ask you about your medical history and will want to exclude other possible causes of facial paralysis.

Your GP may perform blood tests to check for Lyme disease, a condition spread by ticks, which can cause muscle weakness similar to Bell's palsy. He or she may also send you for an MRI (magnetic resonance imaging) scan to check for any signs of a stroke or a brain tumour. An MRI scan uses magnets and radiowaves to produce images of the inside of your brain. Sometimes your GP will refer you to an ear, nose and throat specialist who will perform the blood tests or send you for an MRI scan.

Bell's palsy is idiopathic, which means that its cause is unknown. So, if your doctor finds a specific cause of your facial paralysis, you don't have Bell's palsy.

Treatment of Bell's palsy

For most people, Bell's palsy gets better by itself without any treatment at all. However, you should try to rest as much as possible if you have the condition.

Self-help

Bell's palsy may make it hard to close your eyelid. If this happens to you, you could try using the following to help stop the surface of your eyeball drying out:

Ask your pharmacist for advice on eye drops if you think that they will help you. Tinted sunglasses may also be helpful.

Remember to keep your mouth and teeth clean, as food can become trapped in your mouth.

Medicines

Your doctor may prescribe medicines to increase your chance of recovery.

Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.

Surgery

Surgery or cosmetic procedures may also be used if there are long-term effects of Bell's palsy.

Surgery can be done to relieve pressure on the facial nerve, although this is rarely recommended.

Physical/complementary therapies

Physiotherapy, acupuncture, facial exercises and massage may be used, but more research is needed to prove that these treatments work.

Prevention of Bell's palsy

There is no way of preventing Bell's palsy because its cause is unknown, and there aren't any tests to detect it before symptoms begin.

Further information

Related topics

Sources

This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.

Publication date: March 2009