Hello, writers. SenSho has a family medical issue and can't be here. So you are in my clutches, bwahahaha.
All stories involve protagonists getting into some kind of jeopardy. Sometimes it's just mental or emotional, but often there are physical risks to the conflict that moves the story forward. And unless your protag is some sort of iron-skinned superhero, they may get hurt, or ill. Then what?
What sort of healing is available to the people in your world? Do they rely on herbs? Magic? Are there superstitions that influence how disease and wounds are treated? What is surgery like, if it exists? Are they highly technological, with robots and scanners and nano-whatevers? Or is your protag out in the back of beyond and has to take care of themself or die trying? How do they do that?
Write a scene in which your protag has to deal with a medical issue.