This question was posed to me last week, and I will write a technical response and the actual response given and some practical observations.
47 year old female asked for me to visit to discuss a question of medical ethics. She has been ill for many years, in and out of the hospital for the last five. She says she can take no more, and wishes to be made a hospice patient and thus receive only palliative care. Since among her other ailments she is in kidney failure, by refusing dialysis she would bring life to an end in a fairly short time. her 80 year old father, a Holocaust survivor, is appalled by this wish, and she wishes to ask if she is entitled, by halacha and ethics, to say "I have suffered enough, and am not willing to receive treatment which can only prolong the agony, and offers no chance of a cure."
Response: Patient autonomy and the right to refuse treatment in halacha is a hot new topic, which deserves much more attention. In brief we usually assume that it is mandatory to try and treat any illness, and are enjoined even to be mechalel Shabbos for the sake of chayei sha'ah. Evidently, in the eyes of halacha even if there can be no complete recovery there is still a mandate to treat. We assume that if a procedure is risky it may be refused by the patient, even though a reasonable risk/reward analysis would favor the procedure. The patient can say, "I know this is not good for me," and probably even refuse it for no reason, claiming "I do not wish to take this risk." There is a discussion in Poskim based on the mordechai in Shabbos as to whether the principle of לב יודע מרת נפשו— the heart knows the pain of the soul (in other words, each person knows their own body and feels if something is wrong) applies only to matters of eating, or not. The origin of using this passuk as a principle of halachic medicine is in Gemara Yoma and relates to a sick person sensing whether to fast on Yom Kippur.
This case has some additional complications, out of control diabetes, coronary problems, kidney failure can combine to incapacitate a person, but are not a cause of imminent demise. Furthermore, if a patient is on dialysis, there is often a possibility however remote that they may be a candidate for transplant and be cured.
Actual response: I felt there was an invitation to become involved in a difficult relationship between an ill adult child and an elderly parent, with issues of mutual dependency and hostility. I also felt I was being invited to pass judgement as to whether this woman's ;life is really worthless or not. I could be mistaken, but I felt she needed a psychological work-up more than a halachic work-up. I steered the conversation that way, reassuring her that Jewish law did not rule out the possibility of eventually seeking only palliative care, but suggesting a full case conference with her, her doctor, a psychiatrist and myself before making any decision.
Much more could be said about this, and I will try and write some more mareh mekomos.
Rabbi Avrohom Marmorstein