Futile care, or futile treatment, is an issue in medical ethics, involving judgements that it may variously be unwise, inhumane, or unethical to begin or continue a treatment for putting a disorder into remission or cure, or to treat symptomatically. There are two broad categories of futility: 
- Quantitative futility: Sometimes called physiological futility, the proposed treatment or procedure has an unreasonably low probability of achieving the goal. In instances of physiological futility, the health care professional judges that the desired treatment will not restore or improve function
- Qualitative futility":Proposed interventions of this type can deal with decisions to withhold treatment unlikely to improve a self-limiting condition, or to attempt disease-modifying treatment in a patient judged to be to have a diagnosis incompatible with life, where aggressive treatment cannot affect the outcome.
In either case, "Who determines the harm/benefit ratio and whether it is unreasonable? Are treatments outside of accepted professional practice properly referred to as "futile?" Should rationing decisions be disguised as questions of futility?"
An example of the former might be the use of antibiotics to treat a minor viral infection such as a cold; an example of the latter might be excision of the primary tumor in high-grade metastatic cancer, where the patient's distress is caused by the metastasis, not by local effects of the original disease.
Examples of quantitative care could include:
- full resuscitative measures for an infant with a terminal, congenital condition, such as anencephaly
- Other than comfort care, in a mass casualty situation, such as a patient in the invariably fatal central nervous system presentation of acute radiation syndrome.
As opposed to some of the other examples, which often are case-by-case and dealing with individuals, this may involve decisions for a population as a whole, such as triage for mass casualty incidents when a disaster plan has been invoked.
There may medical precedents or ethical guidelines that apply, which sometimes can conflict with religious or philosophical concerns. Going back to the spiritual father of medicine, Hippocrates, a fundamental principle is "do no harm". In more modern terms, this may mean that the risk of a procedure outweighs any potential benefit, although the risk-benefit balancing will change as medical knowledge.
For example, the Hippocratic Oath contains the promise "I will not use the knife, not even on sufferers from stone, but will withdraw in favor of such men as are engaged in this work", at a time when there was a very major distinction between medicine and surgery. In contrast, appropriate treatment of stones in body organs or ducts can involve effective treatments that are neither strictly medical or surgical, such as lithotripsy or endoscopic procedures to distrupt or remove the object. In some cases, medical therapies avoid surgery with drugs to dissolve the stone or prevent its recurrence.
Doctrine of Double Effect
The Doctrine of Double Effect, articulated by Thomas Aquinas, deals with many issues of ethics, including futility. It deals with situationa in which it is impossible for a person to avoid all harmful action; the question is which action is most ethical. An oft-cited example is seeing an individual about to set fire containing people who cannot escape a fire, but the only way to stop the action, from a distance, is to shoot and kill the person setting the fire.
As a medical example, it may be determined that a patient has end-stage cancer for which only the control of pain can improve quality of the limited life. There is a spectrum of responses that can range from an increased probability (theoretical or real) of causing respiratory failure through the use of adequate doses of opioids to control pain, to passive and active euthanasia.
Potentially shortening life to relieve pain is often more of a theoretical than real situation. When the drugs are prescribed by a physician expert in pain medicine, the current standard is that there is no upper limit to the dose needed to relieve pain, but, given in appropriate quantities and amounts, opioids do not necessarily depress respiratory function. If, however, they do, a new class of ethical issues emerges: is it appropriate to put the patient on an artificial ventilator for the mechanical support of respiration? If it is determined the patient is in end-stage coma, under what circumstances is it appropriate to withdraw that support?
This decision cannot be justified only because the physician does not intend to cause death. "A variety of substantive medical and ethical judgments provide the justificatory context: the patient is terminally ill, there is an urgent need to relieve pain and suffering, death is imminent, and the patient or the patient's proxy consents."
Is the use of opioids in a terminal weaning protocol, preventing the appearance of discomfort, ethical? Under what circumstances, if any, is it appropriate to withdraw respiratory support from an aware but terminal patient, and, if so, is terminal weaning, which will induce unconsciousness, an ethical requirement or a violation of patient autonomy?
Quill et al. have criticized the use of this principal as an argument against such actions as physician-assisted suicide or terminal sedation.  Terminal sedation, often an accepted but controversial practice, involves producing unconsciousness in a consenting and suffering patient for whom no disease-modifying treatment exists, and it is not possible to control discomfort for the conscious patient. In the state of consciousness, the patient will die of dehydration or of effects of the disease.
Some advocates of patient autonomy hold that it is within the rights of a patient to seek aggressive treatment, including alternative medicine, when qualified practitioners, even with multiple opinions, determine they have nothing to offer except comfort care. There are two main issues here: the societal effect of demand on limited resources, and, asssuming that the patient is responsible for the cost and an alternative, for which there is no resource competition, exists. An anecdotal example comes from a case in which a woman with end-stage metastatic breast cancer was told medicine had no cures available, and she sought alternative care from a homeopathic physician who offered cure. 
Rather than obtain hospice and palliative medicine, the woman's husband said he gave her false hope, which "robbed me of precious time to console her, to come to closure, to prepare for her departure." As her surrogate, he stopped what he judged futile treatment.
Death with dignity
Futile care may not always be at the patient or surrogate's demands, although there also can be legitimate disagreement among patient and provider goals. A physician may offer treatment that has some potential to prolong life, but an informed patient may decide that the potential benefit of the treatment is not worth a personal cost. The patient's decision may range from an advance directive that orders no heroic attempts to preserve life, to discontinuing treatment and requesting palliative care, to assisted suicide, to active euthanasia.
There are laws and court decisions both to forbid and encourage the use of what may be judged futile care.
Only two U.S. states, Texas and Virginia, allow physicians to set a time limit, after which care may be ruled futile. 
Right to Life legislation
- Perry, Constance, Futile Treatment, Programs in Humanities and Sciences, College of Nursing and Health Professions, Drexel University
- , Doctrine of Double Effect, Stanford Encyclopedia of Philosophy, April 28, 2004
- Quill, Timothy E.; Rebecca Dresser & Dan W. Brock (December 11, 1997), "The Rule of Double Effect -- A Critique of Its Role in End-of-Life Decision Making", The New England Journal of Medicine 337
- Adler, Jerry (February 4, 2008), "No Way to Treat the Dying", Newsweek
- Quill, Timothy (March 7, 1991), "Death and Dignity: A Case of Individualized Decision Making", New England Journal of Medicine 324: 691
- Marietta, Cynthia S., The Debate Over the Fate of the Texas “Futile-Care” Law: It Is Time for Compromise