We all know where stress comes from, but there's the stress your body goes through when you're sick, or the stress that you go through when you're skiing down a mountain (also called adrenaline, which can affect your blood sugar as well). Anything like that, however long it lasts in your body, is going to screw up your diabetes management.
I just finally got over a cold that I'd been harboring for two weeks, since the 27th. It's not exactly easy when you're me and you can't talk, but then add the fact that everything you do, your diabetes is shooting you down every second of the way. Whenever I have even the slightest inkling of a cold, my blood sugars are absolutely through the roof. I'll be in the higher 300's most of the time, and then, right as the cold is calming down, I'll plummet. And plummet hard.
It's almost the same way when it's finals week at school. Finals week absolutely rips through my body leaving me tired, annoyed, and frankly, a tad bit depressed. But, the blood sugars that come along with finals week are about as unpredictable as the questions on the english test.
Bottom line? Life is stressful. And being diabetic means that you just have to learn how to cope with the stress and roll with the punches.