So one of the characters is in her late 20s, and worked for the corporation since she was a teenager until the last year or so when she became too sick to continue working. Whatever is wrong with her is in some way directly tied to her work, as she recieves a small stipend from the corporation to help support her. She has difficulty breathing, and I've thought about chronic pneumonia but of course that's likely to be a side effect to her illness rather than the primary cause. She may be bedridden for days at a time, but she isn't 100% incapacitated and is able to get out of the house at least occasionally. I've also thought about permanent damage caused by decompression sickness, which is possible but I'm also not sure if it's... Enough? From the research I've done, it seems that the long-term effects of DCS would likely be primarily neurological in nature.
I've researched illnesses that affect divers, tuberculosis & pneumonia, common illnesses on submarines... I'm not really sure where else to go from there. So any ideas or suggestions would be greatly appreciated!