Lots of allergies. Pretty much any common allergy there is, I have it: dust, cats, dogs, pollen... grass... oh, and I've got a fairly long list of medications that I'm allergic to, including nearly every common antibiotic.
Also asthma. Luckily, that's gotten much better over the years. I had to be hooked up to a breathing machine and constantly take steroid meds for the first 10-12 years of my life. Nowadays, the worst that happens is I get a bit wheezy and short of breath on really hot days, or if I exert myself too much.
Oh! And I have a dodgy knee. I've been to physical therapy twice, and it's still no better. The next step is surgery, but it isn't that bad most of the time, so I don't want to pay the money to get it.
And, the last of my recurring problems (that I can think of)... migraines. Damn are they annoying. Nothing like the feeling of someone driving an ice pick through your head, while you feel dizzy, throw up, and can't stand any sort of light...