One of my loved ones suffers from similar issues. Triggers are closed, cramped, stuffy, hot, low air flow, no windows or any combination thereof. Could be a car, bus, plane, train, boat, snorkle mask, dark room, MRI tube, heights, elevators, dehydration, even carnival rides etc.
Turns out this extreme anxiety is the body’s response to unresolved issues in life and therefore the brain is flooded with nerve signals that overload it and cause extreme fight/flight symptoms. Could be repressed child-hood things or current things in life that cause feelings of loss of control. Mentally, it is very difficult to bring the anxiety level down when it hits (so suddenly) so small doses of medicine help with instances such as this young lady on the plane.
It is MUCH more common than most realize but because it is sometimes seen as rather shameful - as many of these posts obviously show - nobody likes to admit it. The cure isn’t straight forward either but a good start is to realize it is a natural response the body has to an extreme amount of inputs. And lots of people have the same condition.
No, I think it’s more about altitude.