The headache no one doubts

There is one pressure-triggered headache with its own diagnostic code. It strikes during landing, sits behind one eye, and is gone again within half an hour.

During an aircraft's descent, cabin pressure has to adjust quickly to a quite different level. For some passengers, that shift triggers a headache so recognisable and so consistent across descriptions that it has been given its own code in the international classification of headache disorders: 10.1.2, "headache attributed to aeroplane travel."

It's rare for a pressure-related headache to be this well defined. Most of the articles on this site are about links that are small, disputed, or only apply to a few people. The aeroplane headache is the opposite story.

The criteria are sharp

A systematic review from 2017 gathered what's known about the condition. The description is consistent across the studies:

• Unilateral — almost always sits behind one eye or in the forehead.
• Severe and stabbing, not a dull sense of pressure.
• Short-lived.
• Occurs mainly during the aircraft's descent — in over 90% of cases during the landing itself.
• Resolves again within 30 minutes of the aircraft landing.

To receive the diagnosis, the classification requires at least two episodes of exactly this type of headache during air travel — and other headache disorders and sinus problems must first be ruled out. The requirement for repetition is not arbitrary. A single headache during one flight could be something else — a sinus infection, a coincidental migraine, too little fluid. It's the pattern recurring flight after flight that makes the diagnosis solid enough to stand on its own.

The sinuses that can't keep up

The proposed mechanism concerns the sinuses. They're air-filled cavities in the skull, connected to the outside through narrow channels. When outside pressure changes faster than the air in the sinus can follow through those channels, an imbalance arises between the pressure inside and out — barotrauma. The 2017 review also points to a second contributing mechanism: vasodilation in the brain, mediated by the signalling substance prostaglandin E2. The phenomenon has its own name in aviation medicine: aerosinusitis.

The large, fast change versus the small, slow one

What makes the aeroplane headache the best-documented pressure-triggered headache there is isn't mystery. It's that the change is large, fast and predictable, every single time an aircraft lands. When the pressure change is large enough and fast enough, there's no doubt in the literature — either that the headache exists, or about what triggers it.

It's worth keeping in mind when reading the rest of this website. The disagreement in research on weather and headache isn't about whether pressure changes can affect the head at all. That question is answered. The disagreement concerns the far smaller, far slower changes we live through day to day — the ones that take hours or days instead of minutes.