@katie02 I also love making my side characters really complex! Sometimes I want to write scenes from their point of view, and bet that would probably help me make my scenes more dynamic too.
For your question, I’m no expert on writing or anything, but as a reader I feel like it would be fine as long as you can make it convincingly plausible. It might seem a little weird, but also, weird unlucky coincidences do happen so…
Also, I’m assuming it’s not fantasy because of those are real-world maladies (to use the fancy term). But if it’s fantasy you could make them cursed or something. Or one of those fantasy stories where stuff just is kind of unrealistic (because it’s not the real world anyway! XD). Anyway, I hope that was at least a little bit helpful!
This is perhaps the greatest risk any of us will ever take: to be seen as we truly are.