Bell's palsy is a condition that causes paralysis on one side of your face. The symptoms usually come on suddenly but have no obvious cause. Most people make a full recovery.
Bell's palsy is caused by damage to your facial nerve, causing weakness to the muscles on one side of your face. Bell's palsy is the most common cause of facial paralysis worldwide.
In the UK, about one in 5,000 people develop Bell's palsy every year. It can affect people of all ages but is most common between the ages of 15 and 60. Men and women are equally affected.
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.
The symptoms of Bell's palsy usually come on suddenly, 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. Symptoms can range from mild to complete paralysis. You may find that on the affected side of your face:
Other symptoms may include the following.
When you smile, you may notice that the affected side of your face appears expressionless, because your muscles are unable to move.
These symptoms may be caused by problems other than Bell's palsy, but if you have them, see your GP immediately for advice. For more information on conditions that can cause similar problems to Bell’s palsy, see our FAQ.
About three-quarters of people with Bell's palsy recover completely. However, if your symptoms don't improve within three to six months, you may find that:
If you have Bell’s palsy after the age of 60, you may not recover as quickly or as fully.
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 Bell’s palsy isn’t known, but the herpes simplex virus, which causes cold sores, may be associated with the condition. If the virus causes infection near your facial nerve, it can become swollen and inflamed.
You may be more likely to develop Bell's palsy if you have diabetes or are pregnant, although the reasons for this aren’t known.
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.
Your GP may refer you to a neurologist (a doctor who specialises in identifying and treating conditions that affect your nervous system, including your brain) or an ear, nose and throat (ENT) specialist. You may also need to see an ophthalmologist (a doctor who specialises in identifying and treating eye conditions) to treat any complications in your eye.
For most people, Bell's palsy gets better by itself without any treatment. Symptoms usually start to improve within three weeks. Almost all people make a complete recovery within six months. 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.
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:
Always read the patient information leaflet that comes with these products and if you have any questions, ask your pharmacist for advice.
If your eye becomes red or painful, or your vision becomes blurred, then it’s important to see your doctor urgently as there may be a scratch on the surface of your eye which could become infected.
You should also stay away from playing ball sports that may injure your affected eye.
Your GP may prescribe you 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. You will usually need to take the tablets for 10 days.
Always ask your GP for advice and read the patient information leaflet that comes with your medicine.
Research has suggested that acupuncture and physical therapies, such as facial exercises and massage, may be beneficial for Bell's palsy. However, more research is needed to confirm whether these treatments are effective.
If your symptoms don't go away after six to nine months, by themselves 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. Speak to your GP for more advice.
Produced by Natalie Heaton, Bupa Health Information Team, September 2012.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.