Bell's palsy

Published by Bupa's Health Information Team, October 2010.

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. The symptoms usually come on suddenly, but have no obvious cause. Most people make a full recovery.

About Bell's palsy

In Bell's palsy the facial nerve supplying the muscles on one side of your face is affected, causing weakness. Bell's palsy is the most common cause of facial paralysis.

Every year about one in 5,000 people develop Bell's palsy in the UK. It can affect people of all ages, including children, but is most common between the ages of 15 and 60. Men and women are equally affected.

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

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

Symptoms of Bell's palsy

The symptoms of Bell's palsy usually come on very quickly, often within a few hours or overnight, and are at their worst within two days.

The main symptom is that one side of your face becomes weak or paralysed. Most people have mild earache or a pain behind their ear. You may also find that on the affected side of your face:

• your eyebrow sags
  
• your eye is difficult to close
  
• your eye is very watery, or alternatively very dry
  
• the corner of your mouth droops, causing saliva and drinks to dribble from your mouth
  
• you become more sensitive to high pitched noise

When you smile, you may notice that the affected side of your face appears expressionless. The amount of weakness people have can vary. Some have only a very mild weakness, but others may have complete paralysis. You may also find that you cannot taste at the front of your tongue or you have an altered sense of taste, but this is uncommon.

These symptoms may be caused by problems other than Bell's palsy. If you have any of these symptoms, see your doctor for advice.

Complications of Bell's palsy

About three-quarters of people with Bell's palsy recover completely. However, some people are left with long-lasting effects. If your symptoms don't improve within three to six months, you may find that:

• the muscles in your face continue to feel tight and weak
  
• you have spontaneous twitches or spasms in your face muscles (also known as synkinesis), causing the corner of your mouth to turn up in a smile when you blink
  
• tears form in your eye on the affected side of your face when you're eating (sometimes called crocodile tears)

Causes of Bell's palsy

The symptoms of Bell's palsy occur when the nerve that controls the muscles in your face becomes inflamed or compressed. The exact cause of this damage, however, is unknown.

It's thought that the herpes simplex virus, which causes cold sores, may be associated with Bell's palsy. If the virus causes infection near your facial nerve, it can become swollen and inflamed.

Diagnosis of Bell's palsy

Your GP will ask about your symptoms and examine you. It's usually possible to diagnose Bell's palsy by looking at how your face is affected on one side.

Depending on your specific symptoms, your GP may refer you to a neurologist (a doctor who specialises in identifying and treating conditions that affect the nervous system, including the brain), or an ear, nose and throat specialist.

Treatment of Bell's palsy

For most people, Bell's palsy gets better by itself without any treatment. If your condition is mild, your GP will usually recommend you take some self-help measures to help you recover. You may, however, need medicines or surgery if your condition is longer-term or more severe.

Self-help

If you have Bell's palsy, you may find it difficult to blink and close your eyelid. This means that the surface of your eye could be at risk of drying out. You can keep your eye moist by using:

• lubricating eye drops such as artificial tears, eye ointments or eye gels
  
• an eye patch or tape to keep your eye closed before you go to sleep

Always read the patient information leaflet that comes with these products and if you have any questions, ask your pharmacist for advice.

Medicines

Your GP may prescribe a steroid such as prednisolone to reduce the inflammation in your facial nerve. If you have this treatment within three days of your symptoms starting, you're more likely to recover. The course of tablets is usually between seven and 10 days.

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

Complementary therapies

It has been suggested that acupuncture and physical therapies such as facial exercises and massage may be beneficial for Bell's palsy, but more research is needed to confirm whether these treatments are effective.

Surgery

If your symptoms don't go away by themselves after about a year, or with medical treatment, cosmetic or reconstructive surgery may be an option. For example, your GP may refer you for treatment if your eyelid doesn't fully close or your smile is crooked. For this treatment speak to your GP for more advice if you're affected.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.