Are they sick? Ill? Dying? Excessively frail?
Yeah I'll put it here.
This includes actually sick, AND characters that people THINK are sick.
This will also include physical and mental disabilities, mental disorders, and neurodevelopmental disorders, and extreme childhood trauma that is addressed in the story beyond the first 5 chapters.
I have not read all of these, many will likely be poor representations. Ymmv.