What Is It?
Bell’s palsy is a sudden weakness or paralysis of the muscles on one side of the face due to inflammation or compression of the facial nerve (cranial nerve VII). It typically causes the face to droop, and the affected person may have difficulty smiling, blinking, or closing their eye on the affected side. Most cases are temporary, with symptoms improving over weeks or months.

Why It Matters
Bell’s palsy can appear without warning, often causing distress due to the facial droop, speech changes, and inability to control expressions. Though many recover fully, early treatment, particularly within 72 hours, can improve outcomes and reduce the risk of lasting facial weakness.

Key Facts (At a Glance)

• Affects ~40,000 people per year in the U.S.

• Often mistaken for stroke, though stroke symptoms usually involve the limbs and are more widespread

• Can affect any age, but is most common between 15–45 years

• Typically unilateral (one-sided facial involvement)

• Recovery starts within 2 weeks, and most recover fully within 3–6 months

How It Affects the Body
The facial nerve (cranial nerve VII) controls the muscles of facial expression, as well as tear production, taste (front two-thirds of the tongue), and some ear functions. When the nerve becomes inflamed, often from a viral infection (like herpes simplex virus), it stops functioning properly. This results in muscle weakness or complete paralysis on one side of the face.

Common Symptoms
Symptoms tend to develop rapidly, reaching their peak within 48 hours:

• Sudden drooping or stiffness on one side of the face

• Inability to close the eye or raise the eyebrow

• Drooling or dry mouth

• Loss of taste on the front part of the tongue

• Tearing or dry eyes

• Pain or discomfort around the jaw or behind the ear

• Sensitivity to sound in one ear (hyperacusis)

Risks & Side Effects

• Temporary facial paralysis (most common)

• Incomplete eye closure, which can lead to dry eye or corneal damage

• In rare cases, permanent facial weakness, synkinesis (involuntary muscle movements), or facial asymmetry

• Psychosocial effects, including embarrassment, anxiety, or depression

Who Should Be Cautious

• People with diabetes (higher risk of Bell’s palsy)

• Pregnant individuals, particularly in the third trimester or postpartum

• Those with recent viral illnesses, including herpes simplex, Epstein-Barr, or influenza

• Individuals with high blood pressure or a weakened immune system

When to See a Doctor
Seek medical attention immediately if you have sudden facial drooping—this may be Bell’s palsy or something more serious like a stroke. Emergency care is needed if:

• You develop weakness on both sides of the face

• Symptoms are accompanied by confusion, vision problems, or limb weakness
  Diagnosis is clinical, but imaging (MRI/CT) or blood tests may be ordered to rule out other causes. Treatment often includes corticosteroids (e.g., prednisone), sometimes combined with antiviral medication if a viral cause is suspected.

Related Conditions / Interactions

• Can be associated with:

  • Lyme disease

  • Sarcoidosis

  • Multiple sclerosis

  • Ramsay Hunt syndrome (a shingles complication affecting the facial nerve)

• Must be differentiated from stroke, brain tumors, and other neurological disorders

• People with prior Bell’s palsy are at increased risk of recurrence

Last Updated: June 15, 2025