Bell's Palsy

Bell's Paralysis, Unilateral Facial Paralysis, Facial Palsy

Basic Information

What is Bell's palsy?

A paralysis or weakness on one side of the face. This is named after the physician who first described it. The onset may be sudden or may come on over several days. In a majority of patients, there is a preceding condition such as stress, fatigue, common cold, stiff neck or shoulder on the affected side. The disorder involves the 7th cranial nerve and the facial muscles supplied by that nerve.

Bell's Palsy signs and symptoms

  • Sudden paralysis on one side of the face, including muscles to the eyelid.
  • Pain behind the ear on the affected side.
  • Flat, expressionless features on one side of the face.
  • Distorted smiles and frowns.
  • Drooling.
  • Changes in taste, salivation or tear formation (sometimes).


Unknown. The paralysis is probably caused by swelling of the facial nerve. The swelling may be caused by a virus; an autoimmune disease; or a decrease in blood flow and pressure on the facial nerve as it passes through the temporal bone of the skull.

Risk increases with

Exposure to cold.

Preventive measures

Cannot be prevented at present.

Expected outcomes

  • Bell's palsy is distressing, but it is not dangerous. The extent of nerve damage determines the extent of recovery.
  • Improvement is gradual and recovery time varies, sometimes requiring many months.
  • Patients with mild facial paralysis usually recover completely within several months. Patients with severe facial paralysis recover completely in 80% to 90% of cases.
  • Surgery can sometimes improve facial appearance and muscle function in patients who do not recover fully.

Possible complications

  • Eye irritation or injury because the eye does not close properly and is exposed to dust. If unprotected, the eye may develop ulcers on the cornea.
  • Tooth decay and gum disease due to reduced saliva and impairment of chewing.
  • Psychological and self-esteem problems.

Bell's palsy treatment

General measures

  • Computed tomography (CT) or magnetic resonance imaging (MRI), and laboratory studies may occasionally be recommended to rule out other causes of pressure on the facial nerve.
  • Electrical tests of the facial nerves (electromyography) may be used to determine the extent of nerve damage.
  • If you have pain, apply heat to the painful area twice a day. Wring out a small towel soaked in hot water and apply for 15 minutes. Cover or close the eye during heat treatments.
  • If you cannot wink or close your eye well, buy a pair of wrap-around, plastic bubble goggles. Wear them to protect your eye from dirt, dust and dryness. You may buy goggles from a sporting goods store or optician.
  • At night, apply an eye patch to shut the lid so the eye stays moist and protected. Occasionally, a patch will be necessary during the daytime.
  • As muscle strength returns, use facial massage and exercises. Massage muscles of the forehead, cheek, lips and eyes using cream or oil. Exercise the weak muscles in front of a mirror. Open and close the eye, wink, smile and bare your teeth. Perform the massage and exercise for 15 or 20 minutes several times a day.
  • Brush and floss teeth more often to keep the mouth healthy.
  • Surgery on the facial nerve (rare).


  • Methylcellulose eye drops for comfort and protection of the exposed eye.
  • Short courses of cortisone drugs are usually beneficial to reduce swelling and inflammation of the affected nerve.
Information Brand Generic Label Rating
Zovirax Zovirax Acyclovir Off-Label

Deltasone (Prednisone), Famvir (Famciclovir)


Maintain your normal activities. Rest does not help Bell's palsy.


A soft diet is often necessary.

Notify your physician if

  • You or a family member has symptoms of Bell's palsy.
  • Your eye becomes red or irritated, despite treatment.
  • You cannot prevent saliva from drooling from your mouth.
  • Pain worsens.
  • Fever occurs.

Last updated 27 May 2015


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