Bell’s Palsy & Facial Nerve Palsy: The Complete Guide to Symptoms, Causes and Treatment

You wake up and notice one side of your face isn’t moving as it should: the corner of your mouth droops, your eye won’t fully close, and your smile is uneven. This frightening moment is the typical start of facial nerve palsy — most often Bell’s palsy. The reassuring news: most cases improve significantly, especially with early treatment and consistent rehabilitation.

What is the facial nerve?

The facial (seventh cranial) nerve leaves the brainstem, travels through a narrow bony canal in the ear and branches out to the muscles of the face. It controls forehead and eyebrow movement, eye closure and blinking, smiling and lip movement, part of taste on the front of the tongue, tear and saliva production, and sound sensitivity in the ear. When it becomes inflamed or compressed, all of these can be affected on one side.

Facial nerve palsy vs. Bell’s palsy

Facial nerve palsy describes weakness of the facial nerve from any cause. Bell’s palsy is the most common type, diagnosed when the paralysis appears suddenly with no other identifiable cause. Less common causes include Ramsay Hunt syndrome (shingles virus), head injury, ear infections or tumors, and surgery.

Symptoms

Symptoms usually appear suddenly and peak within 48–72 hours:

1. Drooping of one side of the face and the mouth corner.
2. Difficulty closing the eye on the affected side.
3. Inability to raise the eyebrow or wrinkle the forehead.
4. Drooling or food and drink escaping from one side of the mouth.
5. Dry eye — or excessive tearing.
6. Changes in taste and increased sensitivity to sound.
7. Mild pain behind the ear, sometimes a day or two before the weakness.

Important: if facial weakness comes with arm or leg weakness, slurred speech or severe dizziness, it may be a stroke. Call emergency services immediately. See Bell’s palsy vs. stroke.

Causes and risk factors

The exact cause is unknown. The leading theory is that a viral infection (such as herpes simplex) triggers inflammation and swelling of the nerve inside its narrow canal. Risk is higher during pregnancy (especially the third trimester), with diabetes, and after upper respiratory infections. The popular belief that cold air directly causes it is not supported by strong evidence.

Diagnosis

Diagnosis is mainly clinical: your doctor asks you to raise your eyebrows, close your eyes, smile and puff your cheeks. Many use the House-Brackmann scale (grade I normal to VI complete paralysis). Scans or tests are only needed for atypical cases, recurrence, or no improvement after several weeks.

Treatment

• Early medication: international guidelines recommend oral steroids within 72 hours of onset for adults; antivirals may be added in some cases. Never self-medicate.
• Eye protection: lubricating drops by day, ointment at night and protecting the eye during sleep. See eye care in facial palsy.
• Facial exercises: gentle, precise, progressive exercises keep muscles supple and improve control. Start with our step-by-step facial palsy exercises.

Will I recover?

In most cases, yes. According to NINDS, most people begin to improve significantly within about two weeks, and around 80% recover completely within 3 months. Some need longer, and a smaller group may keep mild symptoms. Learn more in Bell’s palsy recovery time.

Keep reading: your complete Bell’s palsy library

• Causes & symptoms: What causes Bell’s palsy · Early symptoms · Can cold air cause facial palsy?
• Treatment & recovery: Bell’s palsy treatment · Recovery time · House–Brackmann scale · Electrical stimulation · Can it come back?
• Exercises: Facial palsy exercises · Facial massage · Synkinesis
• Special situations: Ramsay Hunt syndrome · Facial palsy in children · Bell’s palsy in pregnancy

How Raq helps

After your diagnosis, Raq becomes your daily recovery companion: a structured 3-month plan, video and voice guidance, real-time AI guidance through your camera during each exercise, and progress reports that keep you motivated.