Bell's Palsy: Why Half Your Face Drooped Overnight and What Neurologists Do in the First 72 Hours

Bell's palsy is a sudden, temporary weakness or paralysis of the muscles on one side of your face. You may wake up with a drooping mouth, an inability to close one eye, or slurred speech. While it's alarming, most people recover fully. Here's what you need to know—why it happens, how it's diagnosed, and what neurologists do in the critical first 72 hours.

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What Is Bell's Palsy?

Bell's palsy is inflammation of the facial nerve (cranial nerve VII) as it travels through a narrow bony canal in your skull. When the nerve swells or is compressed, signals from your brain to your facial muscles are disrupted, causing weakness or paralysis on one side.

Key points:

• Affects about 20–30 people per 100,000 each year.
• Can occur at any age, but most common between ages 15 and 60.
• Often linked to viral infections, especially herpes simplex (the virus that causes cold sores).

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Why Does Half Your Face Droop Overnight?

The facial nerve controls muscles that lift your eyebrow, close your eyelids, smile, frown and more. Inflammation or compression—often from a viral trigger—interrupts these signals.

Possible triggers:

• Viral reactivation: Herpes simplex virus may reactivate and inflame the facial nerve.
• Immune response: Your body's own defense system may mistakenly attack the facial nerve.
• Other infections: Epstein–Barr virus, varicella-zoster (shingles), and Lyme disease can play a role.

Because the bony canal around the facial nerve is so tight, even mild swelling can pinch the nerve, causing sudden symptoms—often developing over hours, with peak weakness within 48 hours.

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Symptoms to Watch For

Bell's palsy typically affects only one side of the face. Common symptoms include:

Facial changes:

• Sudden drooping of the mouth or eyelid
• Difficulty smiling or frowning
• Inability to fully close one eye

Sensory and other changes:

• Altered taste on the front two-thirds of the tongue
• Increased sensitivity to sound in the affected ear (hyperacusis)
• Reduced tearing or drooling

Red flags requiring urgent care:

• Weakness or numbness in arms or legs
• Trouble speaking, understanding speech, or slurred speech
• Severe headache or neck stiffness
• Vision changes beyond eye closure

If you notice any of these, speak to a doctor immediately—these signs may indicate a stroke or other serious condition.

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How Neurologists Evaluate You in the First 72 Hours

Early assessment guides treatment and rules out other causes of facial paralysis. Here's what neurologists typically do:

1. Thorough medical history

   • Onset and progression of weakness
   • Recent infections (cold sores, shingles)
   • Other neurological symptoms

2. Detailed neurological exam

   • Strength of facial muscles: raising eyebrows, closing eyes, smiling
   • Testing for taste sensation and ear sensitivity
   • Checking reflexes and other cranial nerves

3. Rule out stroke and tumors

   • Imaging (MRI or CT scan) if symptoms are atypical
   • Blood tests for Lyme disease, diabetes, or autoimmune markers

4. Electrophysiological testing (if needed)

   • Electromyography (EMG) may be done after 10–14 days to assess nerve damage and predict recovery

5. Eye-safety assessment

   • Evaluating eyelid closure to prevent corneal drying and injury

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Treatment and Care in the First 72 Hours

Starting treatment early can improve your chances of full recovery. Standard care includes:

• Corticosteroids

• Prednisone or prednisolone, begun within 72 hours of symptom onset
• Typical dose: 50–60 mg daily for 5 days, then tapered over 5 days
• Reduces nerve inflammation and swelling

• Antiviral therapy (in selected cases)

• Acyclovir or valacyclovir if herpes virus is suspected or in severe cases
• Evidence for antivirals is mixed, but often combined with steroids

• Eye protection

• Artificial tears during the day to keep the cornea moist
• Lubricating ointment at night
• Eyelid taping or an eye patch to prevent injury if you can't fully close your eye

• Pain relief

• Over-the-counter pain relievers (ibuprofen, acetaminophen)
• Prescription pain medication if nerve pain is severe

• Facial exercises and physical therapy

• Gentle exercises to stimulate the nerve and maintain muscle tone
• Referral to a facial rehabilitation specialist in some cases

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Prognosis and Recovery

Most people begin to improve within 2 weeks and recover completely within 3–6 months. Recovery milestones:

• 1 month: partial return of movement in mild cases
• 3 months: substantial improvement in most people
• 6 months: near-normal function in 85–90% of cases

Factors that may delay recovery:

• Complete paralysis at onset
• Severe pain around the ear
• Poor nerve response on EMG
• Advanced age or other health conditions (diabetes)

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Monitoring and Follow-Up

After the initial 72 hours, ongoing care may include:

• Regular check-ups to track muscle strength and nerve function
• Eye exams to ensure corneal health
• Adjusting medications if no improvement after 2–3 weeks
• Referral to a neurologist or ENT specialist if symptoms worsen

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Could It Be Something Else?

Facial droop isn't always Bell's palsy. Other possibilities:

• Stroke: often involves additional weakness in the arm or leg
• Ramsay Hunt syndrome: shingles affecting the facial nerve, with rash and ear pain
• Tumors or structural lesions compressing the nerve
• Autoimmune conditions (e.g., Guillain-Barré syndrome)

If you're experiencing sudden facial weakness or drooping and need help determining whether your symptoms align with Bell's Palsy, a free AI-powered symptom checker can provide guidance on whether you should seek immediate medical care.

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When to Seek Immediate Help

Call emergency services or go to the nearest emergency department if you experience:

• Sudden weakness in your arm or leg, especially on one side
• Difficulty speaking or understanding speech
• Severe headache, neck stiffness, or confusion
• New vision changes or loss of coordination

These may be signs of a stroke or other serious neurological event.

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Final Thoughts

Bell's palsy can be frightening, but prompt evaluation and treatment significantly improve outcomes. If you notice sudden facial droop:

1. Seek medical attention—ideally within 72 hours.
2. Start prescribed corticosteroids to reduce inflammation.
3. Protect your eye and follow rehabilitation exercises.
4. Monitor your recovery and follow up with your neurologist.

Most people regain normal function within months. Always speak to a doctor about any serious or life-threatening symptoms.