Sudden Facial Weakness: Bell's Palsy or Stroke—and When Is It an Emergency?

Frequently Asked Questions

What does this condition mean?

Facial weakness can result from the brain's central pathways or the facial nerve. Bell's palsy is acute one-sided peripheral facial nerve weakness developing over hours to a few days when no other cause is identified. Stroke, Ramsay Hunt syndrome, middle-ear disease, trauma, and more slowly progressive nerve lesions can produce a similar appearance.

Does it always mean a serious disease?

Bell's palsy may combine inability to wrinkle the forehead, close the eye fully, and move the corner of the mouth on one side. Stroke may add arm weakness or numbness, impaired speech, vision, or balance; exceptions mean forehead sparing is not diagnostic on its own. Severe ear pain, blisters, hearing change, or vertigo suggest Ramsay Hunt, while gradual progression, recurrence, or both sides being affected suggests another cause.

How is it diagnosed?

The exact onset time is recorded first, followed by a neurological examination including FAST. The clinician assesses every facial region, eye closure, other cranial nerves, the ear, and the mouth. Routine laboratory tests or imaging are not needed for typical uncomplicated Bell's palsy; atypical, progressive, recurrent, or neurologically complex cases receive selected tests and brain imaging. The eye surface is assessed separately.

How is treatment selected?

If Bell's palsy is confirmed, oral corticosteroids are generally recommended within 72 hours for patients aged 16 and over, with individual risks and suitability reviewed. Antiviral treatment alone is not routine; it may be added to steroids in selected severe cases or when a viral cause is suspected. Lubricating drops, overnight protection, and ophthalmology review when needed aim to prevent corneal injury if the eye does not close.

What should I avoid doing at home?

Record the onset time; if stroke signs are present, call emergency services rather than waiting or driving yourself. Do not rub the eye or wear contact lenses, and follow the lubrication and closure technique demonstrated by a clinician. Do not self-start steroids or antivirals; early assessment excludes emergencies and preserves the treatment window.

When is urgent assessment needed?

Facial droop with arm or leg weakness, speech or consciousness change, double vision, new severe imbalance, or a very severe headache is an emergency. Bilateral, recurrent, or worsening weakness after 72 hours, ear blisters, hearing loss, severe vertigo, swallowing difficulty, or a painful red eye also require prompt assessment.