One of the most difficult things I find with having type 1 diabetes is unexpected changes in my insulin needs.
I've been dealing with this recently. Just a couple of months ago, my sugars were running high quite frequently, especially in the evenings. My doctor was recommending more and more insulin to compensate at dinner.
Then, suddenly, my insulin needs suddenly reversed course. I started crashing all the time and had to back off my once-a-day Lantus dose by several units.
Now I'm taking one unit less of my daily Lantus than I used to, but I'm no longer having the same problem with the highs. In fact, my sugars have been under great control, so why am I complaining?
The hardest part of this kind of thing is trying to figure out something that often has no rhyme or reason to it. I have a guess at what could have caused part of the change, but not all of it. I went through a 2- or 3-week period where I wasn't riding my horse, and it was shortly after I started riding again that I started crashing all the time. However, this doesn't explain why I'd been struggling with highs for a month or longer, as I was riding regularly during part of that period.
Whether or not you can find an explanation for abrupt changes in your insulin needs, one thing is for sure — having diabetes requires a lot of vigilance.