My sister has asked this question of a friend of hers who is (I think) in her 60s. I have never heard of this before.
Three times during international flights Ann has experienced light headedness and, on 2 occasions, vomiting. It starts when the cabin settles down for the night and she thinks the air pressure and temperature are altered ‘for the night’. On the flight from the USA [East Coast] to London on their return, Ann very nearly fainted and was put on oxygen for the entire time. She started vomiting and it continued throughout the flight and their day in London. Two other people on the plane fainted and had to also receive oxygen.
For Ann this was the first time the symptoms carried on after landing. It took her some days to fully recover.
At this stage, I do not know which carrier or aircraft but have asked. Has anyone heard of this before?