I almost never get sick. I do however, have bouts of sinus-induced dizzy fits, which reduce me to a bed-ridden mess, with constant major headaches, to the point I need to lay an exact way, or else I can't stop the throbbing and vomiting. The pain is indescribable, closest description I can give, is its probably like someone swinging a shovel into my brain, as hard as they can, every half a second or so.
I get it once or twice a year randomly. Usually Saturday's, and usually lasts 24 - 48 hours. Just had it last weekend infact, but this time I can still somewhat feel the effects of it even a whole week later.
The problem is, the medicine to ease it (never cure it) is worse than not taking medicine at all, so there's literally nothing anyone can do about it.