IT'S no secret that flying is a headache for most, but according to researchers the "aeroplane headache" is the real deal.

The unusual, specific head pain that flares up during landing is more than just a figure of speech, Italian researchers have discovered, and argue it should now be considered a new sub-type of headache, Reuters reported.

"Aeroplane headache" was first reported in medical literature back in 2004, with dozens more cases documented in the following years.

"The 'headache attributed to aeroplane travel', also named 'aeroplane headache', is a recently described headache disorder that appears exclusively in relation to aeroplane flights, in particular during the landing phase," lead researcher Federico Mainardi, of Giovanni e Paolo Hospital in Venice, wrote.

In a recent article in the Cephalalgia journal, Mainardi's team reports on another 75 people with symptoms suggestive of aeroplane headache.

Those individuals contacted doctors after reading a case report by Mainardi published in 2007.

Overall, they fit the features of past cases of aeroplane headache - severe pain on one side of the head that's usually limited to the time the plane was landing.

The headache was almost always short lived, less than 30 minutes for 96 per cent of the people. Only a minority consistently had headaches during landings, and for most it happened on some flights but not on others.

While it's not clear what might trigger the headaches, one theory is that the pain may be related to pressure changes in the sinus cavities, based on the idea that passengers with colds or sinus infections can get severe headaches during take-off or landing.

"Is (aeroplane headache) a unique disorder? I think it is. But others might disagree," R. Allan Purdy, a neurologist and professor at Dalhousie Medical School in Halifax, Canada, who wrote an editorial on the report, said.

"Nobody knows what causes it. Nobody knows how many people have it. Nobody knows what treatments work," he said, but noted that classifying it as a distinct disorder would allow it to be studied more directly.

The good news is that aeroplane headache seems harmless.

"It doesn't appear to be a serious or life-threatening disorder," Purdy said.