Originally Posted by Score8
It seems to be correlated with having some semblance of a sinus infection or cold. Heat definitely helps as did Sudafed prior to travel
That's what I thought too.
But landing in HEL, I did not have a cold or any congestion (nor did I have at any recent point before that). Further, I have flown many times since then with a full-blown cold (including this weekend) and did not experience the severe sinus pain. (I did get some clogged ears.)