I am not a doctor so can't comment on the case of pain. I would guess it is a blockage. I get a little of that, if I have a cold coming on and that is the first symptoms.
In another life i flew unpressurized aircraft for years, in a hot climate. We used to cruise atFL115 or 125 to avoid the convection turbulence. even at my personal max altitude of FL125 there was still a little convection turbulence. I kept the R of D below 500 fpm when possible.
This in my opinion was the lesser of the two evils. One advantage was it used to send most of the pax asleep. The hardest part was to stay awake myself.
Was young and fit in those days.
