Bells palsy occurs when the nerve that controls the facial muscles (facial nerve) becomes inflamed or compressed.
It's not known what causes the facial nerve to become inflamed, although it's thought that a virus, possibly a herpes virus, may be responsible.
The facial nerve passes through a narrow gap of bone near the upper jaw on its way from the brain to the face. If the facial nerve is compressed or swollen it can interfere with the signals that your brain sends to the muscles in your face.
This interference can restrict the blood and oxygen supply to your nerve cells and cause the facial weakness or paralysis that is characteristic of Bell's palsy.
The types of herpes virus thought to cause inflammation of the facial nerve are:
The varicella-zoster virus is a less common cause of Bells palsy than the herpes simplex virus, but can lead to the more serious condition called Ramsay Hunt Syndrome.
In addition to herpes, Bell's palsy has been linked with many other viral infections, such as:
People with diabetes and HIV are thought to be at a higher risk of developing Bell's palsy, although the reason for this is not fully understood.
Bell's palsy is a condition that causes temporary weakness or paralysis of the muscles in one side of the face. It is the most common cause of facial paralysis
The symptoms of Bell's palsy can vary, from a mild numbness of the face, to total paralysis. It can also affect the eyelid and mouth, making it difficult to close and open them.
Bells palsy occurs when the nerve that controls the facial muscles (facial nerve) becomes inflamed or compressed. It's not known what causes the facial nerve to become inflamed, although it's thought that a virus, possibly a herpes virus, may be responsible.
There is no specific test to diagnose Bells palsy. However, tests can be used to rule out other conditions that cause facial paralysis. It's important to see a doctor to determine the cause.
Prednisolone is recommended as the most effective treatment for Bells palsy, and it should be started within 72 hours of the symptoms appearing. Most people recover fully from Bell's palsy within nine months.
A number of complications can occur as a result of Bell's palsy, depending on the extent of nerve damage. About two in 10 people experience long-term problems resulting from Bells palsy.