The preservation of life.
D000328:Adult; D003657:Decision Making; D006262:Health; D006801:Humans; D007231:Infant, Newborn; D008020:Life Support Care; D010819:Physician's Role; D011379:Prognosis; D011788:Quality of Life; D012306:Risk; D018570:Risk Assessment; D019452:Terminally Ill; D028761:Withholding Treatment