I used to live offshore flying the in-field shuttle. Many moons ago, too many to really remember, I continued flying during the last few days of my tour despite having what I thought was "just a cold".
The day after returning home, I collapsed on the way DOWN stairs unable to get my breath. Was diagnosed with Viral Pneumomonia and ended up having my licence medically revoked for 10 weeks!!
Floppy Link has raised a very important point. He suffered a bout of the "leans" while undergoing IF training as a consequence of trying to clear his ears. Luckily for him he was training with another pilot to be "his eyes and ears". Another time, he might have been alone in cloud (inadvertent entry into IMC?) and the outcome could have been more worrying.
Think twice before flying with your head "bunged up" for whatever reason..............