| NPM | nothing per mouth |
|---|---|
| NPO | nothing by mouth [Lat. nulla per os]; nucleus preopticus |
| NPO/HS | nothing by mouth at bedtime [Lat. nulla per os hora somni] |
| PO | by mouth, orally [Lat. per os]; parieto-occipital; parietal operculum; period of onset; perioperativ... |
| po | by mouth [Lat. per os] |