Reviewed September 30, 2026 by the editorial team. Educational content; follow your facility's protocols.
Orders and frequency
Many frequency abbreviations come from Latin. You will still read them in orders and medication records, but spell out anything your facility or ISMP marks as error-prone.
| Abbreviation | Meaning |
|---|---|
| ac | Before meals (ante cibum) |
| pc | After meals (post cibum) |
| bid | Twice a day (bis in die) |
| tid | Three times a day (ter in die) |
| qid | Four times a day (quater in die) |
| qh | Every hour |
| q4h, q6h, q8h, q12h | Every 4, 6, 8 or 12 hours |
| prn | As needed (pro re nata) |
| stat | Immediately (statim) |
| NPO | Nothing by mouth (nil per os) |
| ad lib | As desired, freely |
Q.D. (daily) and Q.O.D. (every other day) are on The Joint Commission Do Not Use list: write "daily" and "every other day". ISMP also advises spelling out hs, qhs and qn as "bedtime" or "nightly".
Routes of administration
Route abbreviations tell you how a medication or fluid is given. A misread route can be as dangerous as a wrong dose.
| Abbreviation | Meaning |
|---|---|
| PO | By mouth (per os) |
| SL | Sublingual, under the tongue |
| IM | Intramuscular |
| IV | Intravenous |
| IVP | Intravenous push |
| IVPB | Intravenous piggyback |
| subcut | Subcutaneous (preferred over SC or SQ) |
| ID | Intradermal |
| PR | Per rectum |
| NG, NGT | Nasogastric, nasogastric tube |
| gtt | Drop, drops |
ISMP lists SC, SQ and sub q as error-prone (read as SL or as "every"), and IN as error-prone (read as IM or IV). Write "subcut" and "intranasal".
Vital signs and assessment
These appear in flowsheets, handoff reports and progress notes.
| Abbreviation | Meaning |
|---|---|
| VS | Vital signs |
| T | Temperature |
| BP | Blood pressure |
| HR | Heart rate |
| RR | Respiratory rate |
| SpO2 | Oxygen saturation by pulse oximetry |
| I&O | Intake and output |
| LOC | Level of consciousness |
| A&O x4 | Alert and oriented to person, place, time and situation |
| PERRLA | Pupils equal, round, reactive to light and accommodation |
| SOB | Shortness of breath |
| N/V | Nausea and vomiting |
| ROM | Range of motion |
| WNL | Within normal limits |
"WNL" hides what you actually assessed. Many facilities prefer that you document the specific findings instead.
Units and measurements
Measurement abbreviations carry the highest risk because a small misread changes the dose by a factor of 10 or 1,000.
| Abbreviation | Meaning |
|---|---|
| mg | Milligram |
| mcg | Microgram (do not write µg) |
| g | Gram |
| kg | Kilogram |
| mL | Milliliter (do not write cc) |
| L | Liter |
| mEq | Milliequivalent |
| mm Hg | Millimeters of mercury |
| cm | Centimeter |
| BSA | Body surface area |
Never abbreviate "unit" or "International Unit". Both U and IU are on The Joint Commission Do Not Use list.
Charting and patient care
These abbreviations show up in nursing notes, care plans and orders for activity and code status.
| Abbreviation | Meaning |
|---|---|
| CC | Chief complaint |
| c/o | Complains of |
| Hx, h/o | History, history of |
| Dx | Diagnosis |
| Tx | Treatment or therapy |
| s/p | Status post (after a procedure or event) |
| ADL | Activities of daily living |
| BRP | Bathroom privileges |
| OOB | Out of bed |
| HOB | Head of bed |
| DNR | Do not resuscitate |
| SBAR | Situation, Background, Assessment, Recommendation |
D/C can mean "discharge" or "discontinue". ISMP recommends writing the full word to avoid stopping medications by mistake.
Departments and hospital units
Unit names appear in transfer orders, handoffs and the census. Local names vary, so learn your hospital's own list.
| Abbreviation | Meaning |
|---|---|
| ED, ER | Emergency department, emergency room |
| ICU | Intensive care unit |
| CCU | Coronary (or critical) care unit |
| NICU | Neonatal intensive care unit |
| PICU | Pediatric intensive care unit |
| OR | Operating room |
| PACU | Post-anesthesia care unit |
| L&D | Labor and delivery |
| Med-Surg | Medical-surgical unit |
| PT, OT | Physical therapy, occupational therapy |
The Joint Commission Do Not Use list
The Joint Commission created its official Do Not Use list in 2004. It applies to all orders, preprinted forms and medication-related documentation in accredited organizations. Each facility may add more items to its own list.
| Do not use | Potential problem | Write instead |
|---|---|---|
| U, u (unit) | Mistaken for 0 (zero), 4 (four) or cc | unit |
| IU (International Unit) | Mistaken for IV (intravenous) or 10 (ten) | International Unit |
| Q.D., QD, q.d., qd (daily) | Mistaken for Q.O.D.; the period after Q can look like an I | daily |
| Q.O.D., QOD, q.o.d., qod (every other day) | Mistaken for Q.D.; the O can look like an I | every other day |
| Trailing zero (X.0 mg) | Decimal point is missed, so 1.0 mg reads as 10 mg | X mg |
| Missing leading zero (.X mg) | Decimal point is missed, so .5 mg reads as 5 mg | 0.X mg |
| MSO4 | Can mean morphine sulfate or magnesium sulfate | morphine sulfate |
| MgSO4 | Confused with morphine sulfate | magnesium sulfate |
A trailing zero is allowed only to show the precision of a reported value, such as lab results, lesion sizes or catheter and tube sizes. It may not be used in medication orders or other medication-related documentation.
ISMP error-prone abbreviations
The Institute for Safe Medication Practices (ISMP) keeps a longer list of abbreviations, symbols and dose designations linked to real medication errors. These items are not banned by The Joint Commission, but ISMP recommends avoiding them. A selection is below.
| Abbreviation | Intended meaning | Write instead |
|---|---|---|
| µg | Microgram | mcg |
| cc | Cubic centimeters | mL |
| SC, SQ, sub q | Subcutaneous | subcut or subcutaneously |
| IN | Intranasal | intranasal or NAS |
| HS, hs | Half-strength; at bedtime | half-strength; bedtime |
| qhs, qn | At bedtime; nightly | nightly or at bedtime |
| TIW | Three times a week | 3 times weekly |
| D/C | Discharge or discontinue | discharge; discontinue |
| AD, AS, AU | Right ear, left ear, each ear | right ear, left ear, each ear |
| OD, OS, OU | Right eye, left eye, each eye | right eye, left eye, each eye |
| IJ | Injection | injection |
| > and < | Greater than; less than | greater than; less than |
| @ | At | at |
| & | And | and |
ISMP recommends avoiding these in all communication about medications, including electronic orders, labels and handoffs, not only in handwriting.
Frequently asked questions
What are the most common nursing abbreviations?
Frequency and route terms such as bid, tid, qid, prn, stat, NPO, PO, IV, IM and SL, plus assessment shorthand such as VS, BP, HR, RR, I&O and SOB. Unit names such as ICU, ED and PACU are also used daily.
What is on The Joint Commission Do Not Use list?
U (unit), IU (International Unit), Q.D. and Q.O.D., trailing zeros and missing leading zeros, and MSO4 and MgSO4. Write "unit", "International Unit", "daily", "every other day", "X mg", "0.X mg", "morphine sulfate" and "magnesium sulfate" instead.
Can nurses still use qd?
No. Q.D. and Q.O.D. are on The Joint Commission Do Not Use list because they are easily confused with each other and with qid. Write "daily" or "every other day".
What is the difference between the Joint Commission list and the ISMP list?
The Joint Commission list is short and required for accredited organizations. The ISMP list is longer and advisory: it collects abbreviations, symbols and dose designations reported in medication errors and recommends safer wording.
Why should you write mL instead of cc?
ISMP reports that a handwritten cc can be misread as u (units), which could lead to a large overdose. mL is the standard unit and is not easily confused.
Who decides which abbreviations are allowed?
Each facility keeps an approved abbreviation list that must include The Joint Commission Do Not Use items. If an abbreviation is not on your facility's list, spell the word out.
More guides and tools
All scales:
Sources: Facts About the Official Do Not Use List of Abbreviations - The Joint Commission · ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations · ISMP List of Error-Prone Abbreviations - AHRQ PSNet · Clinical Abbreviations and Glossary - Loyola University Chicago Stritch School of Medicine · Prescription Abbreviations - Drugs.com. Text written by our editorial team. Reviewed September 30, 2026.