Sure. Thank you for the question.
Really, you can think about these decisions as happening at every stage along somebody's entire journey. Even people who have no symptoms at all may decide that they can justify, for good reasons, that they do not want to have testing, screening, examinations or X-rays. They don't want to know what they would find, or they don't want treatments or don't want to go down that road. They could decide that before they even have any symptoms. They might decide it when they have such symptoms as a chronic cough or loss of weight. They might consider their options and decide not to have the investigations because they don't want to go down that road, even if it would potentially identify a cancer or something that potentially could be treated, with some lengthening of life.
Somebody who's diagnosed with a probable serious condition, such as a mass identified at the first stage of imaging or testing, may decide that they don't want to have further investigations, like a biopsy, to find out what it is. Again, they do not want the treatments that would put their quality of life in jeopardy once they weighed the options. Someone who has a diagnosis of a serious condition may decide that they don't want any recommended treatments once they have the options in front of them. Surgery, chemotherapy, radiation—these all come with very significant impacts on people's quality of life and well-being. People who have kidney failure, for example, may decide that they don't want dialysis—