Bell’s palsy causes temporary paralysis, or palsy, of facial muscles. It occurs when a condition, such as a viral infection, causes inflammation and swelling of the seventh cranial nerve (the nerve that controls facial muscles).
With Bell’s palsy, your face droops on one side or, rarely, both sides. You may have a lopsided smile, or an eyelid that won’t close. These effects typically last several months and go away without treatment. The condition gets its name from Sir Charles Bell, a Scottish surgeon who first described it during the 19th century.
About 40,000 people in the U.S. develop Bell’s palsy every year.
Bell’s palsy affects men and women equally. It typically occurs in people between the ages of 15 and 60. You may be more prone to Bell’s palsy if you are pregnant or have:
It’s unusual to get Bell’s palsy more than once in a lifetime, but it can happen. A recurrence is most likely within two years of the first incident. The facial nerve palsy may affect the same side of your face or the opposite side. You’re more at risk for a recurrence if you have a family history of the disease.
Various viruses may trigger Bell’s palsy. The condition occurs when swelling or inflammation temporarily puts pressure on the nerve that controls facial muscles. This pressure impairs the function of the nerve making it difficult for you to control facial muscles or expressions. As the inflammation subsides, the nerve starts to function again. It may take several months for symptoms to go away.
Symptoms of Bell’s palsy tend to come on suddenly and reach peak severity within 48 to 72 hours. Some people develop mild symptoms. Others experience total paralysis.
Symptoms start to gradually improve in three weeks. Up to 80% of people fully recover and show no signs of Bell’s palsy within three months.
In addition to facial drooping, signs of Bell’s palsy include:
Your healthcare provider can make a diagnosis based on symptoms. Other conditions, including stroke, sarcoidosis & Lyme disease, can also cause facial paralysis. To rule out those causes, you may have one or more of these tests:
Bell’s palsy improves without treatment. Still, your healthcare provider may recommend one or more of these therapies for symptom relief and a faster recovery:
Eight out of 10 people with Bell’s palsy recover fully without any lingering problems. Unfortunately, 20% of people have long-term facial paralysis and drooping. While uncommon, Bell’s palsy can come back, usually within two years of the initial diagnosis. A recurrence may affect the same side of the face or the opposite side.
For unknown reasons, pregnant women are three times more likely to develop Bell’s palsy than women who aren’t expecting. The condition typically occurs during the third trimester. You may be more likely to develop Bell’s palsy while pregnant if you have preeclampsia (high blood pressure) or gestational diabetes.
If your symptoms are severe, your healthcare provider may recommend treatment. Certain treatments, such as oral corticosteroids, may increase your risk of giving birth prematurely before the 37th week of pregnancy. Your healthcare provider can discuss treatment risks and benefits with you.