What does "NPO" stand for?

• A. Not permitted orally
• B. No food or drink by mouth
• C. Non-prescribed order
• D. Nothing by mouth

Answer: (D)

NPO means nothing by mouth. This instruction is used in medical settings to prevent any intake of liquids or solids through the mouth, often before surgery, anesthesia, or certain tests to reduce the risk of choking or aspiration. The term comes from the Latin nil per os, literally “nothing by mouth,” which is why the English expansion most clinicians use is Nothing by mouth.

The other phrasings aren’t the standard way this abbreviation is written or used on orders. For example, saying no food or drink by mouth describes the action, but it isn’t the formal expansion of the acronym. The ideas of “not permitted orally” or “non-prescribed order” don’t match how NPO is used in practice.