Learning word parts lets you work out terms you’ve never seen. Medical terminology shows up on the CCMA, the phlebotomy exam, the PTCB and the NCLEX, and in every chart you’ll read at work.
How to read a medical word
Start at the end. The suffix usually tells you what kind of word it is, such as a condition (-itis, -osis) or a procedure (-ectomy, -scopy). Then read the root to find the body part, and the prefix to see how it’s changed. For example, pericarditis is peri- (around) plus cardi (heart) plus -itis (inflammation).
Prefixes
| Prefix | Meaning |
|---|---|
| a-, an- | without, lacking |
| ab- | away from |
| ante- | before, forward |
| anti- | against |
| auto- | self |
| bi- | two |
| brady- | slow |
| circum- | around |
| dys- | difficult, abnormal |
| endo- | within, inner |
| epi- | upon, outside of |
| eu- | good, well |
| hemi- | half |
| hyper- | above, beyond, excessive |
| hypo- | under, deficient |
| inter- | between |
| intra- | within |
| macro- | large, long, big |
| mal- | bad, abnormal |
| micro- | small |
| mono- | one |
| neo- | new |
| peri- | around |
| poly- | many, excessive |
| post- | behind, after |
| pre- | before, in front |
| sub- | under |
| tachy- | fast |
| trans- | across, through |
| tri- | three |
Suffixes
| Suffix | Meaning |
|---|---|
| -dynia | pain, swelling |
| -cele | bulge |
| -centesis | surgical puncture to remove fluid |
| -cyte | cell |
| -ectomy | cut out, removal |
| -emia | blood condition |
| -gram | recording, a picture |
| -graphy | the process of making a picture |
| -itis | inflammation |
| -lysis | break down, destruction, dissolving |
| -malacia | softening |
| -megaly | enlargement |
| -meter | device used for measuring |
| -metry | measurement of |
| -oid | resembling |
| -ologist | a person working with a specific part of the body or a specific disease |
| -ology | the study of a part of the body |
| -oma | tumor |
| -osis | condition, usually abnormal |
| -otomy | incision, making a cut in |
| -pathy | disease |
| -penia | deficiency, lack of |
| -pexy | surgical fixation |
| -plasty | surgical reconstruction |
| -plegia | paralysis |
| -pnea | breathing |
| -rrhage | bleeding |
| -rrhea | flow or discharge |
| -scopy | use of an instrument for viewing |
| -stomy | surgical opening |
Roots
| Root | Meaning |
|---|---|
| angi, angio | blood vessel |
| arteri, arterio | artery |
| brachi | arm |
| cardi, cardio | heart |
| carp | wrist |
| cephal | head |
| cost | rib |
| crani | skull |
| derm | skin |
| enceph | brain |
| gastr, gastro | stomach |
| hem, hemo, hemat | blood |
| hepat, hepato | liver |
| lingu | tongue |
| mamm, mast | breast |
| my, myo | muscle |
| nephr, ren | kidney |
| neur | nerve |
| odont, dent | tooth |
| ophthalm, ocul | eye |
| oste, osteo | bone |
| ot, oto | ear |
| phleb, ven | vein |
| pneum | air, lung |
| pod, ped | foot |
| rhin | nose |
| thorac | chest |
| thromb | blood clot |
| tympan, myring | eardrum |
| vas, vasc | blood vessel |
TODO: a few definitions differ between the MedlinePlus tutorial and its Appendix A. This list uses "skull" for crani (tutorial page 7), where Appendix A says "brain". Have a reviewer confirm the list before launch.
Sources
- MedlinePlus, National Library of Medicine, Understanding medical words tutorial. How medical words are built, root meanings and the tutorial’s definitions. Checked October 15, 2026.
- MedlinePlus, National Library of Medicine, Appendix A: Word parts and what they mean. Prefix and suffix definitions. Checked October 15, 2026.