Common Medical Abbreviations
Quick answer
Medical abbreviations are the shorthand written on prescriptions, charts, and orders — like BID (twice a day), PRN (as needed), NPO (nothing by mouth), and STAT (immediately). Most come from Latin. The common ones fall into a few groups: how often a medicine is taken (BID, TID, PRN), how it is given (PO by mouth, IV into a vein), chart notes (Hx history, Dx diagnosis, Tx treatment), vital signs (BP, HR, RR), tests (CBC, ECG), and who provides care (MD, RN, NP). Below are the ones you will see most often, grouped by what they describe.
Medical Abbreviations - Essential Clinical Shorthand
The medical abbreviations you actually see on charts, orders, and prescriptions, expanded in plain English. Covers prescription frequency and routes, chart and history shorthand, vital signs, labs and imaging, departments, and provider titles.
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Prescription and frequency (how often to take it)
These come from Latin and are the ones people most often ask about — including the UK set OD, BD, and TDS.
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| BID | B-I-D | Twice a day (bis in die) | |
| TID | T-I-D | Three times a day (ter in die) | |
| QID | Q-I-D | Four times a day (quater in die) | |
| OD | O-D | Once daily (omni die); also 'right eye' in eye care | |
| BD | B-D | Twice a day (UK, same as BID) | |
| TDS | T-D-S | Three times a day (UK, same as TID) | |
| PRN | P-R-N | As needed (pro re nata) | |
| STAT | stat | Immediately (statim) | |
| AC | A-C | Before meals (ante cibum) | |
| PC | P-C | After meals (post cibum) | |
| HS | H-S | At bedtime (hora somni) |
How a medicine is given (route)
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| PO | P-O | By mouth (per os) | |
| IV | I-V | Into a vein (intravenous) | |
| IM | I-M | Into a muscle (intramuscular) | |
| SubQ | sub-Q | Under the skin (subcutaneous; also SC or SQ) | |
| PR | P-R | Rectally (per rectum) | |
| gtt | drops | Drops (guttae) |
Orders and status
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| NPO | N-P-O | Nothing by mouth (nil per os) | |
| NKDA | N-K-D-A | No known drug allergies | |
| DNR | D-N-R | Do not resuscitate | |
| VS | V-S | Vital signs | |
| I&O | I and O | Intake and output | |
| ADL | A-D-L | Activities of daily living | |
| Rx | prescription | Prescription or treatment |
Chart and history shorthand
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| Hx | history | History | |
| Dx | diagnosis | Diagnosis | |
| Tx | treatment | Treatment | |
| Sx | symptoms | Symptoms (sometimes surgery — context matters) | |
| Fx | fracture | Fracture | |
| Bx | biopsy | Biopsy | |
| c/o | complains of | Complains of | |
| SOB | S-O-B | Shortness of breath | |
| N/V | N and V | Nausea and vomiting | |
| h/o | history of | History of | |
| WNL | W-N-L | Within normal limits | |
| y/o | years old | Years old |
Vital signs
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| BP | B-P | Blood pressure | |
| HR | H-R | Heart rate | |
| RR | R-R | Respiratory rate | |
| T | temp | Temperature | |
| SpO2 | S-P-O-two | Oxygen saturation | |
| BMI | B-M-I | Body mass index |
Tests and labs
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| CBC | C-B-C | Complete blood count | |
| BMP | B-M-P | Basic metabolic panel | |
| ECG | E-C-G | Electrocardiogram (also EKG) | |
| CT | C-T | Computed tomography scan | |
| MRI | M-R-I | Magnetic resonance imaging | |
| UA | U-A | Urinalysis | |
| WBC | W-B-C | White blood cell count | |
| Hgb | hemoglobin | Hemoglobin (also Hb) |
Departments and settings
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| ICU | I-C-U | Intensive care unit | |
| ER | E-R | Emergency room (also ED) | |
| OR | O-R | Operating room | |
| OB/GYN | O-B-G-Y-N | Obstetrics and gynecology | |
| ENT | E-N-T | Ear, nose, and throat | |
| Peds | peds | Pediatrics |
Provider titles (types of doctors and staff)
| Medical Abbreviations | Pronunciation | Meaning | Listen |
|---|---|---|---|
| MD | M-D | Doctor of Medicine (physician) | |
| DO | D-O | Doctor of Osteopathic Medicine (physician) | |
| RN | R-N | Registered Nurse | |
| NP | N-P | Nurse Practitioner | |
| PA | P-A | Physician Assistant | |
| PharmD | farm-D | Doctor of Pharmacy |
Frequently asked questions
What are the top 20 medical abbreviations?
Some of the most common are BID (twice a day), TID (three times a day), PRN (as needed), STAT (immediately), PO (by mouth), IV (intravenous), NPO (nothing by mouth), Hx (history), Dx (diagnosis), Tx (treatment), Rx (prescription), BP (blood pressure), HR (heart rate), RR (respiratory rate), CBC (complete blood count), ECG (electrocardiogram), ICU (intensive care unit), ER (emergency room), MD (doctor of medicine), and RN (registered nurse).
What do OD, BD, and TDS mean in medicine?
They are prescription frequencies from Latin, used mainly in the UK and Commonwealth countries. OD means once daily (omni die), BD means twice daily (bis die), and TDS means three times daily (ter die sumendum). In the US the equivalents are once daily, BID, and TID. Note that OD can also mean the right eye in eye care, so context matters.
What are the abbreviations for different types of doctors and providers?
MD is a Doctor of Medicine and DO is a Doctor of Osteopathic Medicine — both are fully licensed physicians. Other common ones include RN (registered nurse), NP (nurse practitioner), PA (physician assistant), and PharmD (doctor of pharmacy).
Are medical abbreviations the same in every country?
Most are widely shared, but some differ by region — for example, UK charts use BD and TDS where US charts use BID and TID. A few abbreviations also have more than one meaning depending on the setting, so the surrounding context always matters.
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