Stress is probably one of the biggest causes of people's physical health falling apart. It can age you prematurely, which is a path you can't undo once it happens. You might stop it from completing, but you'll be starting further up once it kicks in naturally.

And ironically, one of the best treatments for stress I've found is to not pay attention to it. Not suppress it, but simply not care about it. A phrase I keep in my pocket a lot is:

Well, that doesn't mean I get to quit regardless.

Because once you train your mind and body to realize that you can push through stress, it stops effecting you as heavily. Its an old technique used on treating phobias, but it applies pretty well to treating basic stressors as well.