Pikuach nefesh is the Jewish legal principle that saving a human life overrides almost all religious laws.
The Hebrew phrase means “saving a life.” In Jewish law, the preservation of life is treated as a supreme value, so many commandments may be suspended when necessary to prevent death or serious danger. This includes restrictions that would otherwise apply on Shabbat.
The principle is derived through rabbinic interpretation of biblical passages, including the instruction to live by the commandments rather than die because of them. It is not unlimited: Jewish legal authorities discuss specific exceptions and how to determine genuine danger.
Pikuach nefesh should not be confused with a general permission to ignore religious obligations for convenience. Its application concerns a serious threat to life or health and is especially important in medical ethics and emergency decision-making.