One side of the face suddenly droops. It is usually Bell's palsy, sometimes a stroke, and the treatment window is measured in days.
Bell's palsy weakens the muscles on one side of the face, usually over a day or two. The face droops, the smile goes lopsided and one eye is hard to close.
The cause is the seventh cranial nerve, which runs from the brain to the muscles of expression. It becomes inflamed and swollen, often after a viral infection, and stops working.
Below are the six signs. You will also see why the first three days matter more than the rest, and the eye care that protects your sight. None of this replaces being examined.
The six signs that point to Bell's palsy
Symptoms arrive fast, which is part of the picture.
NINDS says they appear suddenly over 48 to 72 hours, and generally begin to improve after a few weeks (NINDS). The speed is a clue, and it is what makes the first days count.
- Sudden weakness on one side of the face. It runs from mild weakness to total paralysis. NINDS says it usually leads to significant facial distortion, and Mayo Clinic says it arrives within hours to days.
- A drooping eyebrow and mouth. The brow on the affected side sits lower and the mouth corner pulls down. Mayo Clinic notes the smile becomes one sided.
- An eyelid that will not close. NINDS lists difficulty closing one eyelid, which dries the eye out. This is the sign that carries the most risk, and the reason eye care matters.
- Drooling from one side of the mouth. The lips cannot seal on the weakened side. Mayo Clinic lists problems eating or drinking for the same reason.
- Pain around the jaw or behind the ear. Both NINDS and Mayo Clinic list this, on the affected side. It can arrive before the weakness does.
- Changes in taste, tears and sound. The facial nerve also affects taste and ear sensation. NINDS lists problems with taste, extra tears in one eye and sensitivity to loud noises.
One thing has to be ruled out first, and it is not subtle. Mayo Clinic says to seek medical help right away if you experience any type of paralysis, because you may be having a stroke (Mayo Clinic, 2024).
It adds that Bell's palsy is not caused by a stroke. But the symptoms of the two conditions are similar. That is a job for an examination, not a search engine.
Why the first three days decide the treatment
Steroids are the usual first treatment, and they are time limited.
NINDS says steroids may be prescribed for new onset Bell's palsy. In most cases they should be started within three days of symptom onset. The aim is to cut the swelling in the nerve, and to raise the chance of recovering facial nerve function.
Antiviral medicines are sometimes added. NINDS says they may also be prescribed to help increase the chance of recovering facial function.
There is no single test that confirms it. NINDS says no specific laboratory test can confirm the diagnosis. Routine laboratory or imaging studies are usually not necessary.
Tests still have a role. NINDS says imaging may be useful if the weakness comes on gradually. The same goes if more than expression, taste and hearing are affected. Tests for Lyme disease and other viruses may be considered.
Note the hour your symptoms started before you go. NINDS says the doctor will ask. That answer decides whether the steroid window is still open.
In most cases, oral steroids should be started within three days of symptom onset.
Keep the three day window with you
Your free one page plan turns this into three steps: what to write down in the first hour, what to ask for at the first visit, and how to protect the eye.
Enter your email to unlock your plan
Your 1-page Bell's palsy plan, unlocked right here.
Your plan is ready
Download or print it below. Save it anywhere.
⬇ Download your plan (PDF)The eye care that protects your sight while you heal
The eye is the part of this that can leave lasting damage.
Mayo Clinic lists partial or complete blindness of the eye that will not close among the complications. It is caused by excessive dryness and scratching of the cornea, the clear protective covering of the eye.
The protection is low tech. NINDS says lubricating eye drops or an eye patch can help keep the eye moist and protect it from debris or injury, especially while sleeping.
Recovery is not always complete. NINDS says the facial weakness may sometimes last longer, or be permanent. Cleveland Clinic covers the same outlook (Cleveland Clinic, 2023).
Mayo Clinic names one more complication. Nerve fibres can regrow unevenly, so smiling may make the eye on the affected side close. The medical name is synkinesis.
Three things people get wrong about Bell's palsy
Three beliefs about Bell's palsy travel further than the evidence behind them.
It is a mild stroke. Mayo Clinic says plainly that Bell's palsy is not caused by a stroke, although the symptoms of the two conditions are similar. That similarity is exactly why any sudden paralysis needs same day medical help.
It only happens to older people. NINDS says Bell's palsy can affect anyone of any sex or age, and that it most often affects people aged 15 to 45. Age is not a filter, in either direction.
You just wait and it goes away. Most people do recover, but the waiting is not the treatment. NINDS puts a three day window on starting oral steroids, and Mayo Clinic ties lasting sight loss to an eye left unprotected while it cannot close.
To your health,
Ageless Coach
Age Strong. Live Long.
This article is education, not medical advice. Bell's palsy is diagnosed and treated by a healthcare professional. Mayo Clinic says to seek medical help right away if you experience any type of paralysis, because you may be having a stroke, so sudden one sided facial weakness is a same day call rather than a next appointment question.