medical problems?

I know for most people weight is primarily a cosmetic issue. I mean, sure, there are health issues attached to it, but the majority of people judge their body based on feeling; they FEEL too fat or too skinny, and that is what drives them to change-- exercise, diet, whatever.
I'm not going to pretend like I'm any different from anyone else. Of course I am self-concious about how I look. I could probably stand to lose a few pounds and that has been true for as long as I can remember. But I don't think, based on conversations I have had over the past few years, that it is as important to me as it is to most women. I rarely notice physical changes in myself until other people point them out to me. I don't expect to be the most beautiful woman in the world, and I am pretty satisfied with the way I look. It's good enough for me.
Okay, so that was basically just a preface to what I'm about to say now. I have been losing weight. For a while now, and not on purpose. In fact, I have been trying pretty hard to maintain my weight and it is dropping anyway.
This concerns me-- from a medical standpoint. Last December I found out I have a blood problem and I started taking meds for it. That was when I started losing weight. At first my doctor said it was just a normal side effect, and I wasn't losing very much or very fast, so it wasn't a big deal, and my body would get used to it and even out eventually. But lately it has been getting more noticeable, and faster. Which isn't right. If my activity level and food intake has stayed the same, there is no reason for me to have been losing wieght.
The thing is, technically, I'm not in any medical danger. This isn't actually a real problem yet. So far, I am just losing my extra fat. And on a cosmetic level, that doesn't bother me. In fact... let it happen. I would love to lose a few pounds. Why not?
BUT. I am a little worried about what this means. It shouldn't be happening, and we can't get it to stop. So say it goes on for a few more months, or a year, or a couple years? Then it will be a real problem. And I will just keep on getting sicker that whole time.
Anyway. Being sick is frustrating me. I don't know what to do. And this isn't even worth whining about yet, but I'll admit it's been bugging me for at least a month now. And I have really complicated and mixed feelings about it.