Virtually any psychological issue.
Besides that, being obese (which usually stems from a psychological issue). Even if you lost the weight, your skin is shot and stretched out. Is over for you.
Being really short as a man is doom in and of itself. Typically anything under 5'6 gets you laughed at by men n women alike. And women won't even consider dating you.
Outside of something obscene like being grotesquely ugly or something, balding is up there.
It's a shame that I feel compelled to wear hats when I go out to bars, etc, because without I'm immediately knocked down a couple of points n look a handful of years older. Women gauk at my hairline, as if to say, "he'd really be something if he wasn't so thin up there".