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.
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
- Pain around the jaw or in or behind your ear on the affected side
- Increased sensitivity to sound on the affected side
- 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.
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.
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)
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
Complications may include:
- Irreversible damage to your facial nerve
- Misdirected regrowth of nerve fibers, resulting in involuntary contraction of certain muscles when you’re trying to move others (synkinesis) — for example, when you smile, the eye on the affected side may close
- Partial or complete blindness of the eye that won’t close due to excessive dryness and scratching of the cornea, the clear protective covering of the eye
Tests and diagnosis
There’s no specific test for Bell’s palsy. Your doctor will look at your face and ask you to move your facial muscles by closing your eyes, lifting your brow, showing your teeth and frowning, among other movements.
- Electromyography (EMG).
- Imaging scans. Magnetic resonance imaging (MRI) or computerized tomography (CT) may be needed .
Treatments and drugs
Most people with Bell’s palsy recover fully — with or without treatment. There’s no one-size-fits-all treatment for Bell’s palsy, but your doctor may suggest medications or physical therapy to help speed your recovery. Surgery is rarely an option for Bell’s palsy.
Commonly used medications to treat Bell’s palsy include:
- Corticosteroids, such as prednisone, are powerful anti-inflammatory agents
- Antiviral drugs
valacyclovir is sometimes given in combination with prednisone in people with severe facial palsy.
Paralyzed muscles can shrink and shorten, causing permanent contractures. A physical therapist can teach you how to massage and exercise your facial muscles to help prevent this from occurring.