One of my main characters has a fatal disease in which he coughs, feels fatigue, and has weak bone structure. These symptoms become prominent throughout the story since he doesn't get proper treatment. (His parents are neglectful.) He develops major depression as a result of being physically and mentally ill. He has no will to live and is spiteful towards everyone since he knows he's going to die. I want to make up a name for it, but I don't want it to sound too fictitious. Any tips?
I mean, you could always look up a real disease that matches what you have in mind. Also, there are plenty of diseases that go undiagnosed because doctors simply can’t figure out what’s wrong. But if you want to make up a name, I’d recommend looking at existing diseases for reference. Some use scientific terms which relate to specific parts of the body or symptoms (such as osteoporosis being made from the old English “osteo” for “bone” and Greek “poros” for “passage/pore” which basically makes a new word meaning porous bones). Or, you could have a more colloquial name as well, by slapping a surname in front of the term “disease.” You can see this in Lou Gehrig’s Disease and Grave’s Disease. (These are often named after the doctors who discover them or notable people who have had the disease)
