| ABBREVIATION |
MEANING |
| N |
Nitrogen, normal (strength of solution) |
| Na |
Sodium |
| NaCl |
Sodium chloride |
| ng |
Nanogram (millimmicron) |
| NGT |
Nasogastric tube |
| NPO |
Nothing by mouth |
| Ob-GYN |
Obstetrics and gynecology |
| 17-OHCS |
17-hydroxcorticosteroids |
| OTC |
Over the counter (a drug that can be obtained without a prescription) |
| oz |
Ounce |
| P |
Phosphorus, pressure, pulse |
| PaCO2 |
Partial pressure of carbon dioxide in arterial blood |
| PaO2 |
Partial pressure of oxygen in arterial blood |
| Pap |
Papanicolaou smear |
| p.c. |
After meals |
| PCO2 |
Partial pressure of carbon dioxide |
| PO2 |
Partial pressure of oxygen |
| peds |
Pediatrics |
| Perrla |
Puplis equal, round, react to light and accommodation |
| pg |
Picogram (micromicrogram) |
| pH |
Hydrogen ion concentration |
| PID |
Pelvic inflammatory disease |
| PKU |
Phenylketonuria |
| PMS |
Premenstrual syndrome |
| P.O. |
By mouth |
| PPD |
Purified protein derivative (of tuberculin) |
| ppm |
Parts per million |
| p.r.n. |
As needed, whenever necessary |
| Pro time |
Prothrombin time |
| psi |
Pounds persquare inch |
| PT |
Physical therapy |
| PTCA |
percutaneous transluminal coronary angioplasty |
| PTH |
Parathyroid horomone |
| PVC |
Premature ventricular contraction |