Medical terminology · Study tool
Medical abbreviations and terms decoder
Look up a charting or prescription abbreviation, break a long medical word into its parts, flip flashcards and try 20 practice questions. Free, and for study only.
- 217 abbreviations
- Word-part decoder
- 20 practice questions
- No sign-up needed
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1 · Abbreviation lookup
What does that abbreviation mean?
Type an abbreviation as it is written on a chart or prescription (bid, NPO, q4h), or a word from its meaning (bedtime, drops). Entries on The Joint Commission “Do Not Use” list and the ISMP error-prone list are flagged with what to write instead.
Common searches
217 abbreviations in the list, all in the printable chart below.
2 · Word decoder
Break a medical word into its parts
Type a word and see its prefix, combining form and suffix with plain meanings, then a plain-English reading. The decoder knows 260 well-established word parts; a word it cannot fully split is shown as far as it goes.
Try one
The parts appear here as you type.
How medical words are put together
- A root (combining form) is usually a body part: cardi/o is the heart. A prefix at the start adds size, speed, place or amount (brady-, peri-). A suffix at the end names a condition, a procedure or a specialty (-itis, -ectomy, -logy).
- The combining vowel, usually o, makes the parts easier to say. It stays before a suffix that starts with a consonant (cardi/o + -logy = cardiology) and is dropped before a suffix that starts with a vowel (cardi/o + -itis = carditis).
- Between two roots the vowel stays, even when the second root starts with a vowel: oste/o + arthr/o + -itis = osteoarthritis.
- Not every word has all three parts: dyspnea is a prefix and a suffix, gastric is a root and a suffix.
3 · Flashcards
30 word-part flashcards
Tap a card (or press Enter) to flip it. Use the arrows or the left and right keys to move, and shuffle when the order starts to feel familiar.
Card 1 of 30. Word part: cardi/o.
See all 30 cards as a list
- cardi/oheart
- gastr/ostomach
- hepat/oliver
- nephr/okidney
- neur/onerve
- oste/obone
- arthr/ojoint
- my/omuscle
- derm/o, dermat/oskin
- encephal/obrain
- rhin/onose
- pneum/o, pneumon/olung, air
- cholecyst/ogallbladder
- enter/ointestine
- phleb/ovein
- hem/o, hemat/oblood
- lith/ostone
- -itisinflammation
- -ectomysurgical removal
- -megalyenlargement
- -scopyexamination with a scope
- -pathydisease
- -algiapain
- -emiablood condition
- -tomy, -stomya cut into; a surgical opening
- brady- / tachy-slow / fast
- hyper- / hypo-excessive / too little
- dys-difficult, abnormal
- a-, an-without, lacking
- peri- / endo-around / within
4 · Practice questions
20 practice questions
Abbreviations and word parts, multiple choice, one at a time. Every answer is explained, and your score is free: no sign-up needed.
Question 1 of 20
On a prescription, bid means
Bonus · unlocks with your email
The printable chart, the 7-day plan and 40 more questions
- Printable abbreviation chart: every one of the 217 abbreviations on this page by group, with the Joint Commission “Do Not Use” list on top and the ISMP flags beside each entry. It prints on its own, three to four pages.
- 7-day word-part plan: one word family a day (heart, digestion, breathing, kidneys, bones, nerves, then prefixes and suffixes), eight words to decode each day with the answers.
- 40 more practice questions, every answer explained.
Enter your email in the box above and the bonus opens right here, and stays open on this browser.
Sources
Where the facts come from
Every meaning, origin and flag on this page is reworded from one of these public sources. Check anything important against your program’s materials and your facility’s own approved list.
- The Joint Commission: Facts about the “Do Not Use” list
- ISMP: List of Error-Prone Abbreviations, Symbols, and Dose Designations (2024)
- NIH MedlinePlus: Understanding Medical Words tutorial
- NIH MedlinePlus: Word parts and what they mean (Appendix A)
- NIH MedlinePlus: Abbreviations (Appendix B)
- NCI SEER Training Modules: Formation of medical terms
- Minnesota Board of Pharmacy: Partial list of prescription abbreviations
- North Carolina Office of EMS: Approved medical abbreviations (2023)
- Northwestern Health Sciences University library: Building medical terms
Questions
Common questions
Twice a day, from the Latin bis in die. It is one of the frequency abbreviations used on prescriptions: tid (ter in die) is three times a day and qid (quater in die) is four times a day.
Three times a day, from the Latin ter in die. It is not the same as TIW (three times a week), which ISMP says to write out as “3 times weekly” because the two are confused.
Four times a day, from the Latin quater in die. A poorly written QD (daily) can look like QID, which is why QD is on the Joint Commission “Do Not Use” list and “daily” is written instead.
As needed, from the Latin pro re nata. A PRN order also names the reason and a limit, such as “every 6 hours as needed for pain”.
A short list from The Joint Commission of abbreviations that must not appear in orders or medication-related documentation that is handwritten, typed as free text or pre-printed: U and u (write “unit”), IU (write “International Unit”), QD and QOD and their variants (write “daily” and “every other day”), a trailing zero such as 1.0 mg and a missing leading zero such as .5 mg (write 1 mg and 0.5 mg), and MS, MSO4 and MgSO4 (write “morphine sulfate” or “magnesium sulfate”). ISMP publishes a longer list of error-prone abbreviations; this page flags both.
No. This is a study aid for people in medical assisting, billing and coding, health information and nursing programs, and for staff who read charts. It does not diagnose, treat or tell anyone what to do for a patient. Your facility’s own approved abbreviation list and your instructor come first.
The lookup, the decoder, the flashcards and the 20 practice questions with your score are free with no sign-up. An email unlocks the bonus: the printable chart, the 7-day plan and 40 more questions.