Short answer: because the air pressure in the cabin changes by about a quarter of an atmosphere between the ground and cruise, and the only way to equalise the air trapped behind your eardrum is a tube the width of a pencil lead that opens for a fraction of a second when you swallow. On the way up, the trapped air expands and vents itself easily; on the way down, it contracts, the eardrum is pulled inward, and the tube has to be actively opened against a pressure difference that gets larger the longer you wait. That is why the pain is on descent, why it is worse with a cold, and why the fixes are about timing. In the one randomised trial of a decongestant, 32% of adults on pseudoephedrine had ear discomfort against 62% on placebo.
The mechanism first, because once you see it the advice writes itself.
The pressure change you are equalising
Aircraft cabins are pressurised, but not to sea level. Federal regulations require the cabin altitude to stay at or below 8,000 feet (2,440 m) in normal flight, and most airliners cruise with the cabin at 6,000 to 8,000 feet. In pressure terms:
| Condition | Air pressure | Relative to sea level |
|---|---|---|
| Sea level | 1,013 hPa | 100% |
| Cabin at 6,000 ft | ~812 hPa | ~80% |
| Cabin at 8,000 ft | ~753 hPa | ~74% |
| Change, ground to cruise | ~260 hPa | About a quarter of an atmosphere |
The middle ear is a small air-filled space behind the eardrum. It connects to the back of the nose through the Eustachian tube, which is normally closed and opens briefly when you swallow, yawn or chew. If the pressure in the middle ear matches the pressure in the cabin, the eardrum sits neutral and you hear normally. If they differ, the eardrum bows toward the lower pressure, stretches, and hurts.
On climb, cabin pressure falls, so the air in the middle ear is now at higher pressure than the cabin. It pushes the eardrum outward, the tube is forced open from inside, the excess vents into the nose with a pop, and the problem solves itself. Most people notice the climb only as a few pops.
On descent, cabin pressure rises, so the middle ear is now at lower pressure than the cabin. The eardrum is pushed inward. To equalise, the tube has to open so that air can flow into the middle ear, and a tube being squeezed shut by the surrounding pressure difference does not open on its own. It has to be opened, by swallowing, yawning or a manoeuvre, and the larger the difference has grown, the harder that is. Wait long enough and the tube locks: the pressure difference holds it closed and no amount of swallowing opens it. That is the pain, and the muffled hearing, that arrives with the seatbelt sign.
Why it is worse with a cold
The Eustachian tube runs through soft tissue in the back of the nose. Anything that swells that tissue, a cold, sinus infection, hay fever, or a flare of chronic rhinitis, narrows the tube and makes it harder to open against pressure. Mirza and Richardson's review of otic barotrauma from air travel identifies upper-respiratory infection as the main risk factor for the injury version of this, when the pressure difference gets large enough to bleed into the middle ear or tear the drum. Children are more susceptible because the tube is narrower and more horizontal, and because they do not swallow deliberately on descent.
Muhm and colleagues' New England Journal of Medicine chamber study of cabin altitude found that discomfort of all kinds rose with cabin altitude and was measurably worse at 8,000 feet than at 6,000, which is the reason newer aircraft that hold the cabin at a lower altitude are noticeably easier on the ears: less pressure to equalise on the way down.
The manoeuvres, in order of how well they work
All of them do the same thing: open the tube so air can pass into the middle ear on descent. The differences are in how reliably they open it and how much force they use.
| Method | How | Effectiveness | Caution |
|---|---|---|---|
| Swallowing, repeatedly | Sip water, suck a sweet, chew gum | Good if started early; the muscles that swallow are the ones that open the tube | Not enough once the tube has locked |
| Yawning | Real or forced; the jaw movement pulls the tube open | Good | Same |
| Toynbee manoeuvre | Pinch the nose and swallow | Good; gentler than Valsalva | — |
| Valsalva manoeuvre | Pinch the nose, close the mouth, blow gently as if to inflate the cheeks | Very effective; the standard fix | Gently. A hard blow can push infected mucus into the middle ear or, rarely, damage the drum. Stop if it hurts |
| Frenzel manoeuvre | Pinch the nose, close the throat, push with the tongue against the roof of the mouth | Very effective, the diver's method; less pressure on the chest | Takes practice |
| Pressure-equalising earplugs | Slow the rate of pressure change at the ear | Modest; they buy time, they do not equalise | Do not replace the manoeuvres |
| Hot towels over the ears, the "cup trick" | Warmth and steam | Placebo, mostly | Harmless |
The variable that matters more than the choice of manoeuvre is when you start. Equalise every thirty seconds or so from the moment descent begins, when the difference is small, and the tube opens easily. Wait until the ears hurt and the difference has grown to a level where the tube is held shut. A small correction every half-minute beats one large one at the end.
The seatbelt-sign moment, roughly twenty to thirty minutes before landing, is the cue. Wake up for it, or ask to be woken.
The one drug that was tested
Csortan and colleagues (1994) ran a randomised, double-blind, placebo-controlled trial of 120 mg of pseudoephedrine taken 30 minutes before departure, in adults who had previously experienced ear pain flying. Of 190 who completed the study, 32% of the pseudoephedrine group reported ear discomfort during the flight against 62% of the placebo group. That is about a halving, from a single dose of an ordinary decongestant. A later trial of the same approach in children found no benefit, and children got more side effects, so the finding is an adult one.
Ear discomfort during flight occurred in 32% of passengers given 120 mg pseudoephedrine before departure and in 62% given placebo.
Csortan, Jones, Haan & Brown, Annals of Emergency Medicine, 1994 — summarised from the results
Two caveats. Pseudoephedrine raises heart rate and blood pressure, interacts with several medications, and is not appropriate for everyone; it is behind the pharmacy counter in the US for reasons unrelated to ears. And the trial dosed before departure; for a long flight the drug's effect may have faded by descent, and some clinicians suggest timing a dose for an hour before landing instead, which the trial did not test.
Nasal decongestant sprays such as oxymetazoline work on the same tissue by a local route, with fewer whole-body effects, and are commonly recommended for the same purpose; the trial evidence for them in flight is thinner than for the tablet. Antihistamines help only if allergy is the cause of the swelling.
Barotrauma: when it is more than discomfort
Most airplane ear is transient: pressure, fullness, muffled hearing and pain that resolve within minutes to hours of landing once the tube finally opens. Otic barotrauma is the injury version, when the pressure difference is large enough to damage tissue. MedlinePlus and the otolaryngology guidance describe the signs to take seriously:
| Symptom | What it suggests | Action |
|---|---|---|
| Pressure and pain that resolve within hours of landing | Ordinary barotrauma, no injury | Nothing; equalise earlier next time |
| Muffled hearing lasting more than a day | Fluid or blood in the middle ear | See a doctor; usually resolves, occasionally needs treatment |
| Severe pain, then sudden relief, then discharge | Possible eardrum perforation | See a doctor; most heal on their own, some need care |
| Dizziness or vertigo, ringing, sudden hearing loss | Inner-ear barotrauma, rare | Urgent assessment |
| Recurrent problems every flight despite equalising | Eustachian tube dysfunction | An ENT can assess and offer treatments, including ventilation tubes for frequent flyers with children |
Flying with an active ear infection, or shortly after ear surgery, is the situation in which barotrauma is most likely, and the honest advice from the specialty is not to fly if you can avoid it, and to use a decongestant and equalise aggressively if you cannot.
What to actually do
Before the flight: if you have a cold, a sinus infection or bad hay fever, consider whether to fly. If you must, an adult without contraindications can take a decongestant 30 to 60 minutes before descent is expected, or before departure on a short flight. Children: no decongestants; plan on feeding, drinking or a dummy on descent.
On climb: nothing needed; let the ears pop.
At the start of descent, roughly 30 minutes before landing: stay awake. Swallow, yawn or do a gentle Valsalva every half-minute. Do not wait for pain.
If an ear locks: sit up, tilt the head so the blocked ear is up, and try a gentle Valsalva or Frenzel. Do not blow hard. If it will not clear, it usually will within an hour of landing; a decongestant spray after landing helps.
After landing: muffled hearing that persists beyond a day, discharge, dizziness or sudden hearing loss are reasons to see a doctor.
Frequent flyers with recurring trouble: an ENT visit. Eustachian tube dysfunction is treatable, and for children who fly often, ventilation tubes are a recognised option.
The sleep-on-a-plane advice and this article collide at one point: the best sleep is through the middle of the flight, and the ears need you awake for the last half hour. Set an alarm.
Questions people ask
Why do my ears hurt on a plane? Because cabin pressure changes by about a quarter of an atmosphere between the ground and cruise, and the Eustachian tube that equalises the middle ear opens easily on the way up but must be actively opened, against a growing pressure difference, on the way down. The pain is the eardrum being pushed inward on descent.
Why do my ears hurt more when the plane is landing? On descent the middle ear is at lower pressure than the cabin, so air must flow in through the Eustachian tube, which is squeezed shut by the same pressure difference. On climb the reverse happens and the tube vents on its own. Descent needs deliberate equalising; climb does not.
How do I stop my ears from hurting on a plane? Start equalising as soon as descent begins and repeat every 30 seconds: swallow, yawn, or pinch the nose and gently blow or swallow. Do not wait for pain. Adults without contraindications can take a decongestant beforehand; in a trial it halved ear discomfort.
Does pseudoephedrine help with airplane ear? In a randomised trial of adults prone to ear pain, 120 mg before departure reduced ear discomfort from 62% to 32%. It is not appropriate for everyone, and a trial in children found no benefit, so it is an adult option to discuss with a pharmacist.
Why do my ears hurt on a plane when I have a cold? Swollen tissue in the back of the nose narrows the Eustachian tube, making it harder to open against the pressure difference on descent. Colds and sinus infections are the main risk factor for ear barotrauma from flying.
How long does airplane ear last? Usually minutes to a few hours after landing, once the tube opens. Muffled hearing beyond a day, discharge, dizziness or sudden hearing loss are signs of injury and should be assessed.
Can flying damage your ears? Rarely, yes: a large enough pressure difference can cause fluid or bleeding in the middle ear or a perforated eardrum, mostly in people flying with an infection. Most cases heal on their own; inner-ear symptoms such as vertigo need prompt care.
Do earplugs help with ear pain on planes? Pressure-equalising earplugs slow the rate of pressure change at the ear, which gives the tube more time. They reduce discomfort for some people but do not equalise the middle ear; swallowing and the manoeuvres still do the work.
Why do babies cry on descent? The same mechanism, in a narrower tube, without deliberate swallowing. Feeding, a bottle or a dummy during descent makes the baby swallow, which opens the tube.
Is the Valsalva manoeuvre safe on a plane? Yes, done gently: pinch the nose, close the mouth, and blow softly until the ears pop. Blowing hard can force mucus into the middle ear or, rarely, injure the drum. Stop if it hurts and try swallowing with the nose pinched instead.
This article covers travel physiology for general information and is not medical advice. Decongestants have contraindications, including heart conditions, high blood pressure and some medications; check with a pharmacist or doctor. Persistent hearing changes, discharge or vertigo after a flight need medical assessment.
References
- Federal Aviation Administration. 14 CFR § 25.841 Pressurized cabins. ecfr.gov
- Csortan, E., Jones, J., Haan, M., & Brown, M. (1994). Efficacy of Pseudoephedrine for the Prevention of Barotrauma During Air Travel. Annals of Emergency Medicine, 23(6), 1324–1327. doi:10.1016/S0196-0644(94)70359-0
- Mirza, S., & Richardson, H. (2005). Otic barotrauma from air travel. The Journal of Laryngology & Otology, 119(5), 366–370. doi:10.1258/0022215053945723
- MedlinePlus, U.S. National Library of Medicine. Ear barotrauma. medlineplus.gov
- American Academy of Otolaryngology–Head and Neck Surgery. Ears and Altitude (Barotrauma). enthealth.org
- Muhm, J.M., Rock, P.B., McMullin, D.L., et al. (2007). Effect of Aircraft-Cabin Altitude on Passenger Discomfort. New England Journal of Medicine, 357(1), 18–27. doi:10.1056/NEJMoa062770
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