How long does Bell's palsy last?

Most people notice the first movement returning within a few weeks and recover over the following months; public health guidance puts the usual range at a few weeks to about six months. How complete recovery is depends mainly on how severe the weakness was at its worst and whether steroids were started early. About 70 percent of people whose face is completely paralyzed recover fully, and up to 94 percent of those with incomplete weakness do. A minority are left with residual weakness or with linked movements that appear as the nerve regrows.

I am past the 72-hour window. Is it too late to treat?

The benefit of steroids is best established within about three days. Beyond that the evidence thins out and guidelines say the benefit is less clear, but many clinicians still start them within the first week because the downside is small. The rest of the care matters at any point. Eye protection, an accurate diagnosis, and looking for the mimics are worth doing whenever you present.

Is Bell's palsy dangerous?

Bell's palsy itself is not life-threatening, and most people recover. The two real risks are missing something else that looks like it, above all a stroke, and damage to the eye when the lid cannot close. That is why sudden facial weakness is assessed the same day, and why eye care starts at once.

Does Bell's palsy hurt?

Often there is a dull ache behind or below the ear, starting a day or two before the weakness and fading over the first week or two. Severe pain, or a rash in or around the ear, points to Ramsay Hunt syndrome, which is shingles of the facial nerve and is treated differently.

Can stress cause Bell's palsy?

Not directly. The immediate cause is inflammation of the facial nerve, usually from a reactivated virus. Stress, sleep loss, and other illness can weaken the immune system's control of dormant viruses, which is why Bell's palsy so often follows a hard stretch.

Can Bell's palsy happen more than once?

It can, though it is uncommon. Repeat episodes, weakness on both sides, or weakness that is slowly progressive rather than sudden point away from ordinary Bell's palsy and toward another cause: Lyme disease, sarcoidosis, a tumor along the nerve, or an inflammatory condition. Those need imaging and blood work.

What is the difference between Bell's palsy and facial palsy?

Facial palsy means weakness of the muscles of the face from a problem with the facial nerve, whatever the cause. Bell's palsy is the most common cause and the label used when the onset is sudden and no other cause, such as Lyme disease, shingles, a tumor, or a stroke, is found.

Bell's Palsy: Causes, Symptoms, and Recovery Time

Bell's Palsy: Telling It From a Stroke, and What Recovery Looks Like

Bell's palsy is sudden weakness of one side of the face from inflammation of the facial nerve, usually after a viral infection. It comes on over hours to a day and affects the forehead as well as the mouth, which is the main difference from a stroke. Most people recover over weeks to months, and steroids started within the first three days improve the odds.

Medically reviewed by Dr. Achillefs Ntranos, MDPublished September 14, 2024Updated September 3, 202610 min read

A face that suddenly droops on one side is frightening for a good reason: it is also what a stroke can look like. Telling the two apart is the first job, and it comes down largely to the forehead. Once a stroke is excluded, Bell's palsy usually has a good outcome, especially when treated in the first few days.

What is Bell's palsy?

The facial nerve, the seventh cranial nerve, drives every muscle of expression on its side of the face. When it stops conducting, that side goes slack over hours, worst within a day or two. Facial palsy is the general term for that weakness; Bell's palsy is the most common cause, and the name used when no other cause is found.

Drooping of the mouth and eyelid, a lopsided smile, a forehead that will not wrinkle
An eye that will not close, watering or feeling dry and gritty
Loss of taste on the front of the tongue on that side
Sound feels too loud in that ear
A dull ache behind the ear, often a day or two before the weakness
Drooling, and food collecting in the cheek

The ache of Bell's palsy is dull. Sharp, electric facial pain without weakness is a different condition, trigeminal neuralgia.

A calm face with a delicate copper facial-nerve motif on one side.

Bell's palsy or a stroke

Use this to understand, not to decide at home

The forehead sign below is reliable when a clinician examines the whole nervous system, not on its own, and it is unreliable in a mirror at three in the morning. Have any sudden facial weakness assessed the same day, and if it comes with arm or leg weakness, trouble speaking, numbness, vision loss, or a severe headache, call 911. Stroke treatment is time-critical.

The facial nerve runs the whole side of the face. The brain sends signals to the forehead from both sides, so a stroke usually leaves the forehead working. That single difference is the most useful sign there is.

Sign	Bell's palsy	Stroke
Forehead and eyebrow	Weak; cannot wrinkle or raise that side	Usually spared; the forehead still moves
Eye closure	Often cannot close fully	Usually closes normally
Arm and leg	Normal strength	Often weak on the same side
Speech	Blurred only by the slack lip	Words or understanding affected
Onset	Over hours to a day, often after an earache	Seconds to minutes
Other clues	Taste changed, sound loud in that ear	Numbness, vision loss, imbalance

What causes Bell's palsy

The nerve travels through a narrow bony canal in the skull. When it swells, it is compressed against the bone and stops conducting. The trigger is usually viral.

Herpes simplex, the cold sore virus, is the most commonly implicated
Varicella-zoster, the chickenpox and shingles virus, particularly with a rash in or around the ear
Epstein-Barr, influenza, COVID-19, and other respiratory viruses
Lyme disease, the reason we ask about tick exposure and travel

It is more common in pregnancy, in people with diabetes, and after a recent respiratory infection. Stress does not cause Bell's palsy directly. Stress, poor sleep, and illness are thought to loosen the immune system's hold on dormant viruses, which is probably the link so many people notice.

Facial nerve branches extending from near the ear to the forehead, eyelid, cheek, and mouth. — Bell's palsy affects the nerve that moves the muscles on one side of the face.

How it is diagnosed

A typical case needs no testing. The diagnosis is clinical, and the work is in checking that the pattern fits and excluding the mimics: stroke, multiple sclerosis, Lyme disease, a tumor along the nerve, which causes slowly progressive rather than sudden weakness, and Ramsay Hunt syndrome, shingles of the facial nerve, which is treated differently and easy to miss without looking in the ear.

Testing is added when the case is atypical: blood work including Lyme where exposure is possible, an MRI when the weakness is progressive or slow to recover, and EMG in severe cases to gauge the injury and predict recovery.

Treatment and recovery

First 72 hours: steroids
A short course of oral steroids reduces the swelling in the canal. Starting within 72 hours is the window in the otolaryngology clinical practice guideline, and it matches the trials the American Academy of Neurology relied on, which all treated within three days. It measurably improves the chance of full recovery. An antiviral is sometimes added, but it does not work alone, and the American Academy of Neurology found no evidence identifying a subgroup that benefits from adding one. A rash in or around the ear is a different diagnosis, Ramsay Hunt syndrome, which is shingles of the facial nerve and is treated on its own terms.
From day one: protect the eye
If the eyelid does not close, the cornea can dry out and ulcerate. Eye protection is set up at the first visit: lubricating drops through the day, ointment at night, and, when the lid does not close in sleep, a way of keeping it closed that a clinician shows you, because tape applied badly can scratch the eye. This is as important as the medication, and the part most often neglected.
The first weeks: first movement
Most people notice the first flicker of return within the first few weeks. Facial exercises and physical therapy help, and forcing it does not.
The following months: the rest
Recovery continues over months. The nerve can regrow into the wrong muscles, producing linked movements such as the eye narrowing when you smile, or tearing when you eat. Targeted facial therapy reduces those, and a small number of people are left with some lasting weakness or tightness.

An eye, unbranded eye drops, and a soft eye patch. — Care includes treatment of the facial weakness and protection of an eye that does not close fully.

When to see a neurologist

Sudden facial weakness goes to an emergency department first, to exclude a stroke and start treatment inside the window where it works best. A neurologist is the right next step, and sooner if the weakness affects both sides, recurs, or came with hearing changes or a rash in the ear.

Dr. Achillefs Ntranos, MD sees these patients in Beverly Hills and Los Angeles and by video across California. Say when booking that you have new facial weakness, because the steroid window is short. A first visit confirms the diagnosis, starts or adjusts steroids if you are still inside the window, sets up eye protection, and looks for the features that suggest something other than Bell's palsy. We do not perform EMG here; when it is useful we arrange it nearby and review the result with you. You can request a visit in Beverly Hills or Los Angeles, or by video anywhere in California.