Developed a weird pneumonic condition at 14, that thankfully went away with a two month treatment. The downside, it had developed over 4 months before it really got bad, so it made my mom think she was the worse mother in the world when she was told that if I had been taken to the doctor a week later, I would had needed to be taken to a hospital for more serious treatment. The upside, none: it definitely is no fun to feel like you're drowning on your own mucose.
The OTHER annoying sickness I got was something girls can relate to, but guys can't: ovary cysts.