Bell’s palsy: Causes, treatment, and symptoms

Bell’s Palsy, or facial palsy, is a paralysis or severe weakness of the facial muscles on one side of the face.

It is believed to be due to a swelling of the nerve that controls the muscles of the face.

It can be worrying, but most people make a full recovery.

What is Bell’s palsy?

A patient with Bell's palsy on the left side
A patient with Bell’s palsy on the right side of his face, with the muscles on this side appearing to be paralyzed.
Image credit: Dr. James Heilman

Bell’s palsy involves a weakness or paralysis on one side of the face. Symptoms often appear first thing one morning. A person wakes up and finds that one side of their face does not move.

The person may find that they suddenly cannot control their facial muscles, usually on one side. The affected side of the face tends to droop. The weakness may also affect saliva and tear production, and the sense of taste.

Many people are afraid they are having a stroke, but if the weakness or paralysis only affects the face, it is more likely to be Bell’s palsy.

Approximately 1 in 5,000 people develop Bell’s palsy each year. It is classed as a relatively rare condition.

In very rare cases, Bell’s palsy can affect both sides of the face.


The facial nerve controls most of the muscles in the face and parts of the ear. The facial nerve goes through a narrow gap of bone from the brain to the face.

If the facial nerve is inflamed, it will press against the cheekbone or may pinch in the narrow gap. This can result in damage to the protective covering of the nerve.

If the protective covering of the nerve becomes damaged, the signals that travel from the brain to the muscles in the face may not be transmitted properly, leading to weakened or paralyzed facial muscles. This is Bell’s palsy.

The exact reason why this happens is unclear.

It may result when a virus, usually the herpes virus, inflames the nerve. This is the same virus that causes cold sores and genital herpes.

Other viruses that have been linked to Bell’s palsy include:

chickenpox and shingles virus

coldsores and genital herpes virus

Epstein-Barr virus, or EBV, responsible for mononucleosis


mumps virus

influenza B

hand-foot-and-mouth disease (coxsackievirus)

Bell’s palsy risk factors

pregnant lady lying on her side
Women who are in the last trimester of their pregnancy or who have just given birth may be at risk from Bell’s palsy.

Some risk factors have been established.

Links have been found between migraine and facial and limb weakness. A study carried out in 2015 found that people with migraine may have a higher risk of Bell’s palsy.

The condition more commonly affects:

people aged 15 to 60 years

those with diabetes or upper respiratory diseases

women during pregnancy, especially in the third trimester

women who gave birth less than 1 week ago

Bell’s palsy affects men and women equally.

a woman having difficulty breathing
An allergic reaction to prednisolone, such as difficulty breathing, should immediately be reported to a healthcare professional.

Any allergic reaction to prednisolone should be reported to the doctor immediately.

Allergy symptoms may include:


breathing difficulties

swelling of the face




If the patient feels dizzy or drowsy they should refrain from driving or operating heavy machinery. As this symptom may not appear straight away, it is advisable to wait a day before driving or operating machinery.

Doctors usually reduce the dose gradually towards the end of the course of steroid medication. This helps prevent withdrawal symptoms, such as vomiting or tiredness.

Leave a Reply

Your email address will not be published. Required fields are marked *