You’ll see abbreviations in orders, charts and handoffs from your first clinical shift, and they show up on certification exams too. NHA’s CCMA test plan, for example, includes The Joint Commission’s “Do Not Use” list. Facilities keep their own approved lists, so check yours.
The Joint Commission’s “Do Not Use” list
The Joint Commission requires these items to stay out of all orders and medication-related documentation, handwritten or electronic.
| Do not use | Why it’s a problem | Write instead |
|---|---|---|
| U, u (unit) | Mistaken for 0, 4 or cc | unit |
| IU (International Unit) | Mistaken for IV or 10 | International Unit |
| Q.D., QD, q.d., qd (daily) | Mistaken for each other, and the period after the Q can look like an I | daily |
| Q.O.D., QOD, q.o.d, qod (every other day) | Mistaken for each other, and the O can look like an I | every other day |
| Trailing zero (X.0 mg) | The decimal point is missed | X mg |
| Missing leading zero (.X mg) | The decimal point is missed | 0.X mg |
| MS | Can mean morphine sulfate or magnesium sulfate | the full drug name |
| MSO4 and MgSO4 | Confused for one another | the full drug name |
A trailing zero is allowed only where it shows the precision of a reported value, such as a lab result or a catheter size. It’s never allowed in a medication order. The Joint Commission doesn’t publish a list of approved abbreviations.
Common medical abbreviations
| Abbreviation | Meaning |
|---|---|
| ABG | Arterial blood gases |
| AFIB | Atrial fibrillation |
| AMI | Acute myocardial infarction |
| BID | Twice a day |
| BMI | Body mass index |
| BP | Blood pressure |
| BPH | Benign prostatic hypertrophy |
| BUN | Blood urea nitrogen |
| CABG | Coronary artery bypass graft |
| CAD | Coronary artery disease |
| CBC | Complete blood count |
| CHF | Congestive heart failure |
| CNS | Central nervous system |
| COPD | Chronic obstructive pulmonary disease |
| CPR | Cardiopulmonary resuscitation |
| CRP | C-reactive protein |
| CSF | Cerebrospinal fluid |
| CVA | Cerebrovascular accident |
| CXR | Chest x-ray |
| DJD | Degenerative joint disease |
| DM | Diabetes mellitus |
| DVT | Deep-vein thrombosis |
| DX | Diagnosis |
| ECG, EKG | Electrocardiogram |
| EEG | Electroencephalogram |
| ESR | Erythrocyte sedimentation rate |
| GERD | Gastroesophageal reflux disease |
| GFR | Glomerular filtration rate |
| GI | Gastrointestinal |
| gtt | Drop (WisTech Open) |
| GU | Genitourinary |
| HCT | Hematocrit |
| HDL | High density lipoprotein |
| HGB | Hemoglobin |
| HTN | Hypertension |
| ICU | Intensive care unit |
| IM | Intramuscular |
| IV | Intravenous |
| LDL | Low density lipoprotein |
| LFT | Liver function tests |
| MI | Myocardial infarction |
| MRI | Magnetic resonance imaging |
| MRSA | Methicillin-resistant Staphylococcus aureus |
| NG | Nasogastric |
| NKDA | No known drug allergies |
| NPO | Nothing by mouth, from the Latin nil per os (WisTech Open) |
| NSAID | Non-steroidal anti-inflammatory drug |
| PO | By mouth (WisTech Open) |
| PRN | As needed |
| PT | Prothrombin time |
| PTT | Partial thromboplastin time |
| QID | Four times a day |
| RBC | Red blood cell |
| Rx | Prescription |
| SOB | Shortness of breath |
| stat | Immediately (WisTech Open) |
| subcut | Subcutaneous, injected into the innermost layer of skin (WisTech Open) |
| TIA | Transient ischemic attack |
| TID | Three times a day |
| URI | Upper respiratory infection |
| UTI | Urinary tract infection |
| WBC | White blood cell |
MedlinePlus also lists MS as multiple sclerosis. In medication orders and medication-related documentation, The Joint Commission prohibits MS because it can mean morphine sulfate or magnesium sulfate, so write the full term instead. The Joint Commission points to the Institute for Safe Medication Practices (ISMP) list of error-prone abbreviations for more items to avoid, and that list includes SC and SQ.
TODO: no open source found for HR (heart rate). Add it once there's a citable definition.
Sources
- MedlinePlus, National Library of Medicine, Appendix B: Some common abbreviations. The common abbreviations and their meanings, except the rows credited to WisTech Open. Checked October 16, 2026.
- WisTech Open, CC BY 4.0, Nursing Dosage Calculations, glossary. PO, stat, gtt and subcutaneous. Checked October 16, 2026.
- WisTech Open, CC BY 4.0, Medical Terminology 2e, 12.9 glossary. NPO. Checked October 16, 2026.
- The Joint Commission, Standards FAQ on abbreviations, acronyms, symbols and dose designations (updated April 21, 2026). The current required "Do Not Use" list, where it applies, and the trailing zero exception. Checked October 16, 2026.
- National Healthcareer Association, CCMA test plan. The CCMA test plan includes The Joint Commission’s “Do Not Use” list. Checked October 15, 2026.
- Institute for Safe Medication Practices, List of error-prone abbreviations, symbols and dose designations. SC and SQ are on ISMP’s error-prone list. Checked October 16, 2026.
- The Joint Commission, via the Internet Archive, Official "Do Not Use" list fact sheet (archived January 19, 2022). The potential problem with each item and what to write instead. Checked October 16, 2026.