What does NPO mean on a prescription?
NPO means nothing by mouth — no food, drink, or oral medicines. It is used before surgery, scans, and some procedures, and when swallowing is unsafe.
- Means:
- nothing by mouth
- From:
- nil per os
- Type:
- How to take it
- Also written:
- npo, n.p.o., NPO, nil by mouth
What it means in practice
NPO exists to keep the stomach empty, which lowers the risk of inhaling stomach contents under anaesthesia. UK notes often say “nil by mouth” instead. The order usually comes with a time, such as NPO after midnight, and the team will tell you which regular medicines to take with a sip of water.
Example on a prescription
NPO after midnight before procedure
Have nothing to eat or drink from midnight until after the procedure.
Commonly confused with
- POPO means by mouth. NPO is the opposite — nothing by mouth.
Worth knowing
Do not stop regular medicines on your own because of an NPO order. Ask the team which ones to take with a sip of water — withholding some, such as certain heart or anti-seizure medicines, carries its own risk.
Frequently asked questions
What does NPO mean in hospital?
Nothing by mouth — no food, no drink and no oral medicines until the order is lifted.
Can I drink water if I am NPO?
Not unless you are told otherwise. Some teams allow sips of water for medicines or clear fluids up to a cut-off; confirm with the nurse or anaesthetist.
Related abbreviations
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This page explains prescription notation for general information. It is not medical advice and does not replace your prescriber or pharmacist. If a label is unclear or differs from what you were told, check with your pharmacy before taking the medicine.