to treat the disease to save the patient

To risk or sacrifice one's own life to save or help other people.

to risk or give one's own life to save someone else's life

(idiom) to jump into a well to save someone; figuratively, to do something foolish that harms oneself without benefiting others, or to try to do good in a wrong-headed way

saving a human life is more meritorious than building a seven-story pagoda; used to emphasize the supreme value of saving someone's life