Bell’s Palsy
Sudden weakness of one side of the face, caused by an inflamed facial nerve. It looks frightening and must be checked urgently to rule out a stroke, but most people recover fully, and steroid tablets started within 72 hours improve the odds.
Quick answer: Bell’s palsy is sudden weakness on one side of the face caused by an inflamed facial nerve. Because it can look like a stroke, get checked urgently. Steroid tablets started within 72 hours improve recovery. Most people start improving within 3 weeks and recover fully within months. Protecting the eye while it can’t close matters too.
How common. About 1 in 4,000 people a year, most often aged 15 to 60, men and women equally. It’s more common in pregnancy (especially late pregnancy and just after the birth) and in people with diabetes.
Causes. The facial nerve swells inside its narrow bony channel through the skull. Reactivation of a virus, such as the cold sore virus, is suspected but not proven. It isn’t caused by a stroke, and it isn’t contagious.
Symptoms. Weakness comes on over hours, peaking within about 3 days. On the affected side: a drooping mouth and eyebrow, trouble closing the eye, a flattened forehead that won’t wrinkle, drooling and food collecting in the cheek. Often pain behind the ear, a dry or watery eye, loud sounds seeming too loud, and changed taste.
Stroke or Bell’s palsy?. A stroke usually spares the forehead (you can still raise both eyebrows) and often comes with arm or leg weakness, slurred speech, confusion or vision problems. But it isn’t always easy to tell, so sudden facial weakness always needs checking straight away. More in our stroke deep dive.
Other look-alikes. Ramsay Hunt syndrome (shingles of the facial nerve, with a painful rash or blisters in or around the ear), middle ear infection, Lyme disease after travel to affected areas, and rarely a tumour, which usually comes on slowly over weeks to months. Weakness on both sides suggests a different cause.
How it’s diagnosed. From the examination, once other causes are ruled out. Blood tests and scans aren’t usually needed, unless the picture is unusual or it isn’t improving after about 3 weeks.
The Bell’s palsy ladder
Steroids are the treatment with strong evidence. Eye care protects you while the nerve heals.
- Step 1 · Self-careProtect the eyeLubricating eye drops by day, a thicker eye ointment at night, taping the eyelid shut for sleep, and glasses or sunglasses outdoors.
- Works
- Prevents a dry, scratched cornea while the eye can’t close
- Cost
- About $10–25
- How long
- Until the eye closes fully
- Watch for
- Eye pain, redness or blurred vision needs a same-day check.
Your eye can’t blink for itself right now. Be its eyelid.
- Step 2 · PrescriptionPrednisolone tablets within 72 hoursA short course of steroid tablets, ideally started as soon as possible.
- Works
- Strong evidence. In a large trial, full recovery at 9 months was 94% with prednisolone vs 82% without. A Cochrane review found 1 extra full recovery for every 10 people treated
- Cost
- About $10–20; PBS
- How long
- About 10 days
- Watch for
- Raised blood sugar (check closely with diabetes), sleep and mood changes, indigestion.
The 72-hour window is real. Don’t wait it out at home.
- Step 3 · PrescriptionAdding an antiviral (aciclovir or valaciclovir)Sometimes added for severe or complete weakness.
- Works
- A Cochrane review found adding an antiviral to steroids may make little or no difference; antivirals alone are less effective than steroids
- Cost
- About $20–60
- How long
- About 7 days
- Watch for
- Used routinely for Ramsay Hunt syndrome, which is a different condition.
The steroids do the heavy lifting here.
- Step 4 · Allied healthFacial physiotherapyFacial exercises, massage and retraining, especially if recovery is slow.
- Works
- Evidence is limited, but it may help people with slower recovery or unwanted linked movements
- Cost
- About $80–120 a session
- How long
- Weeks to months
- Watch for
- Avoid forceful exercises early on, which may encourage unwanted movements later.
Gentle and precise beats grimacing at the mirror.
- Step 5 · SpecialistBotulinum toxin or surgery for lasting problemsFor people left with weakness, tightness or unwanted linked movements months later.
- Works
- Helps selected people with long-term effects
- Cost
- Medicare rebates; fees vary
- How long
- Varies
- Watch for
- Usually considered after at least 6 to 12 months.
For the few, not the first months.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Electrical stimulation of the faceThere’s little good evidence it helps recovery.
What you can do
- See a doctor the same day it starts, so steroids can begin within 72 hours.
- Use eye drops by day and ointment at night, and tape the eye shut for sleep if it won’t close.
- Eat and drink on the strong side and rinse your mouth after meals.
- Use a straw if drinks dribble.
- Take paracetamol or ibuprofen for pain behind the ear.
- Be patient: improvement usually starts within 2 to 3 weeks.
See your GP if
- You have new facial weakness (same day, or call 000 if any stroke signs)
- It isn’t improving after 3 weeks
- Weakness is getting worse over weeks, or it comes back
- Your eye is red, sore or your vision changes
Call 000 (Australia) or your local emergency number if facial weakness comes with weakness or numbness in an arm or leg, slurred or muddled speech, confusion, vision loss, a severe headache, or trouble walking. Think F.A.S.T.: Face, Arms, Speech, Time. See a doctor the same day for a rash or blisters in or around the ear, or weakness on both sides of the face.
Outlook. Most people start to improve within 2 to 3 weeks and recover fully within 3 to 6 months. About 7 in 10 recover fully even without treatment, and early steroids raise that further. A minority are left with some weakness, tightness or unwanted linked movements, such as the eye closing when you smile. It comes back in a small number of people.
In Australia. The Stroke Foundation’s F.A.S.T. test covers facial droop. If you’re unsure whether it’s Bell’s palsy or a stroke, call 000.
Common questions
Is Bell’s palsy a stroke?
No. Bell’s palsy is inflammation of the facial nerve, not a problem in the brain. But the face can look similar, so any sudden facial weakness needs urgent medical review to rule out a stroke.
How long does Bell’s palsy last?
Most people start to improve within 2 to 3 weeks and recover fully within 3 to 6 months. Some take up to 9 months, and a minority have lasting weakness.
What causes Bell’s palsy?
Swelling of the facial nerve inside its narrow bony channel. A virus, such as the cold sore virus, is suspected. It’s more common in pregnancy and in people with diabetes.
Do I need steroids for Bell’s palsy?
Steroid tablets started within 72 hours are recommended for most adults. They raise the chance of full recovery: in a large trial, 94 in 100 recovered fully by 9 months with prednisolone vs 82 in 100 without.
Can Bell’s palsy come back?
It can, but only in a small number of people. Weakness that keeps returning or slowly worsens needs further tests.
How do I protect my eye with Bell’s palsy?
Use lubricating eye drops through the day and an eye ointment at night, tape the eyelid shut for sleep, and wear glasses or sunglasses outside. See a doctor the same day for eye pain, redness or blurred vision.
Evidence and more information
- Madhok et al, Cochrane 2016: Corticosteroids for Bell’s palsy
- Sullivan et al, N Engl J Med 2007: Early treatment with prednisolone or acyclovir in Bell’s palsy
- Gagyor et al, Cochrane 2019: Antiviral treatment for Bell’s palsy
- NHS: Bell’s palsy
maladywise.com/bells-palsy/