Some bioethical theories, including the teaching of the Catholic Church, distinguish ordinary and extraordinary care. Ordinary care is always obligatory. Extraordinary care is care whose provision involves a disproportionately great burden on the patient or community, and hence is not morally obligatory.

On the Catholic version of the distinction, the natural provision of life necessities, such as food, air, and water, is an example of ordinary care, although it does not exhaust ordinary care, since easily performed medical procedures (that do not impose an undue burden on patient and community) will also be ordinary care.