Signs and symptoms of Bell's palsy - Mayo Clinic News Network

Health & Wellness

Signs and symptoms of Bell’s palsy

By
Dana Sparks

April 26, 2024

a medical chart with words that ask about Bell's palsy risk

Bell's palsy causes sudden weakness in your facial muscles. This makes half of your face appear to droop. Your smile is one-sided, and your eye on that side resists closing.

Bell's palsy, also known as facial palsy, can occur at any age. The exact cause is unknown, but it's believed to be the result of swelling and inflammation of the nerve that controls the muscles on one side of your face. It may be a reaction that occurs after a viral infection.

For most people, Bell's palsy is temporary. Symptoms usually start to improve within a few weeks, with complete recovery in about six months. A small number of people continue to have some Bell's palsy symptoms for life. Rarely, Bell's palsy can recur.

Signs and symptoms of Bell's palsy come on suddenly and may include:

Rapid onset of mild weakness to total paralysis on one side of your face — occurring within hours to days
Facial droop and difficulty making facial expressions, such as closing your eye or smiling
Drooling
Pain around the jaw or in or behind your ear on the affected side
Increased sensitivity to sound on the affected side
Headache
A decrease in your ability to taste
Changes in the amount of tears and saliva you produce

In rare cases, Bell's palsy can affect the nerves on both sides of your face.

Causes

Facial nerve

Although the exact reason Bell's palsy occurs isn't clear, it's often linked to exposure to a viral infection. Viruses that have been linked to Bell's palsy include the virus that causes:

Cold sores and genital herpes (herpes simplex)
Chickenpox and shingles (herpes zoster)
Mononucleosis (Epstein-Barr)
Cytomegalovirus infections
Respiratory illnesses (adenovirus)
German measles (rubella)
Mumps (mumps virus)
Flu (influenza B)
Hand-foot-and-mouth disease (coxsackievirus)

With Bell's palsy, the nerve that controls your facial muscles, which passes through a narrow corridor of bone on its way to your face, becomes inflamed and swollen — usually related to a viral infection. Besides facial muscles, the nerve affects tears, saliva, taste and a small bone in the middle of your ear.

a medical illustration of a man with facial paralysis

Risk factors

Bell's palsy occurs more often in people who:

Are pregnant, especially during the third trimester, or who are in the first week after giving birth
Have an upper respiratory infection, such as the flu or a cold
Have diabetes

Also, some people who have recurrent attacks of Bell's palsy, which are rare, have a family history of recurrent attacks. In those cases, there may be a genetic predisposition to Bell's palsy.

When to see a doctor

Seek immediate medical help if you experience any type of paralysis because you may be having a stroke. Bell's palsy is not caused by a stroke. See your doctor if you experience facial weakness or drooping to determine the underlying cause and severity of the illness.