A 27-year-old man with no known health problems was in his car when he let out a long yawn. Right afterward, the right side of his face stopped working properly. His right ear felt full, his cheek and tongue went numb, and he could not close his right eye.
Doctors in Italy concluded that the yawn had set off a rare injury called alternobaric facial palsy, in which a sudden pressure imbalance in the middle ear temporarily knocks out the facial nerve. The case, from specialists at the University of Verona and the University of Padua, was published online in CRANIO in September 2025 and appears in the journal's May 2026 issue.
The twist is that yawning usually sits on the other side of the equation. Medical references list it among the simple moves that equalize middle ear pressure and can make this kind of palsy fade.
Ear Fullness, Numbness, and an Eye That Would Not Close
On examination, the man had a peripheral facial palsy on the right side, graded IV on the House-Brackmann scale, which runs from I for normal function to VI for total paralysis. He also had a positive Bell's sign, meaning his eye rolled upward when he tried to shut it.
The rest of his neurological exam was normal. CT and MRI scans of his brain and temporal bones, the skull bones that house the ear, showed no lesions, and other causes were ruled out. Given the abrupt onset, the absence of any structural problem, and the exclusion of other explanations, the team diagnosed alternobaric facial palsy.
That makes it a diagnosis of exclusion. No test captured the pressure change as it happened.
How Middle Ear Pressure Can Squeeze the Facial Nerve
The facial nerve runs through a bony canal as it crosses the middle ear on its way to the muscles of the face. According to the StatPearls reference on alternobaric facial paresis, published through the National Library of Medicine, the condition arises when pressure in the middle ear compresses that nerve, producing symptoms that resemble Bell's palsy.
The reference describes two usual ingredients: a Eustachian tube that does not equalize pressure well, and a gap in the bony covering of the nerve's canal, known as a dehiscence. Neither is exotic. Based on U.S. national survey data, Eustachian tube dysfunction has been estimated to affect 4.6% of adults, and studies commonly find facial canal gaps in 18% to 33% of people examined, StatPearls notes. High-resolution CT misses many of these gaps, with a sensitivity of about 66%.
Most reported cases involve scuba diving, air travel, or altitude. A systematic review of the medical literature by Houston researchers, published in 2023, identified 49 cases, with an average age of 34 and 80% of patients male. A March 2026 report in Frontiers in Audiology and Otology described a 25-year-old woman whose right-sided facial palsy struck on five separate commercial flights, only once the plane reached cruising altitude, and cleared within 30 minutes each time. High-resolution CT showed unusually extensive air cells in her temporal bones and tiny bony gaps where her facial nerve canal met structures of the inner ear. A ventilation tube placed in her eardrum stopped the episodes on later flights.
Getting the diagnosis right has consequences. In divers, StatPearls notes, the condition has been mistaken for decompression sickness or air embolism, leading to unnecessary recompression treatment and restrictions on diving. The reverse mistake is dangerous, too: facial weakness that spares the forehead points toward a central cause such as stroke and does not fit this pressure-related palsy.
What sets the Italian case apart is the trigger. The authors called it an atypical one, "a simple yawn," and said it shows that alternobaric mechanisms deserve consideration in sudden facial palsy, even in everyday settings.
Steroids, Eye Care, and a Full Recovery in Three Weeks
The man was treated with the steroid prednisone, starting at 50 milligrams and tapered over three weeks, along with eye care and close follow-up.
He recovered fully within three weeks. At checkups 3, 6, and 12 months later, the palsy had not returned, the authors reported.
That course fits the reference description of the condition as usually transient. StatPearls cautions, however, that if the pressure is not relieved, lasting facial nerve weakness similar to that seen in Bell's palsy can follow. Until the face recovers, the biggest risk is damage to the cornea from an eye that cannot blink fully, which is why eye protection is part of treatment.
A Rare Trigger, Not a Reason to Fear Yawning
This is a single case, and the authors describe alternobaric palsy set off by routine activities as exceedingly uncommon. Nothing in the report suggests ordinary yawning poses a meaningful risk for most people. Why this man was vulnerable remains unclear. His imaging did not show a structural defect, although CT can miss small gaps in the facial canal.
The more practical lesson concerns any sudden facial weakness. Bell's palsy is the most common explanation, but the list of possible causes is broad and includes stroke, trauma, infection, tumors, and autoimmune disease, according to a StatPearls review of facial nerve palsy last updated in April 2026.
That breadth is why sudden drooping of the face calls for prompt medical evaluation rather than waiting to see whether it passes. Only an exam, and sometimes imaging, can sort out which cause is responsible, and anyone whose facial weakness comes with other sudden neurological symptoms should seek emergency care.
Key Questions Answered
What happened to the 27-year-old?
Right after a prolonged yawn in his car, he developed weakness on the right side of his face, ear fullness, cheek and tongue numbness, and an inability to close his right eye.
What is alternobaric facial palsy?
It is a rare, usually temporary facial nerve injury caused when a pressure imbalance in the middle ear compresses the facial nerve. It is most often linked to diving, flying, or altitude.
Why is a yawn such an unusual trigger?
Yawning is normally listed among the maneuvers that help equalize middle ear pressure. In this case, doctors concluded it did the opposite.
Did he recover?
Yes. After a three-week prednisone taper, eye care, and close follow-up, he recovered fully within three weeks, with no recurrence at 3, 6, or 12 months.
Should people worry about yawning?
No. This is a single, exceptionally rare case. The broader lesson is that any sudden facial weakness needs prompt medical evaluation, because causes range from Bell's palsy to stroke.
