Below are the most common interior root words used in medical terminology. If you landed on this page from a web search, be sure to check out our Finding Root Words page. It contains the exterior root words.
| Medical Terminology – Interior Root Words | |
| abdomin/o | abdomen |
| aden/o | gland |
| adren/o | adrenal gland |
| alveoli/i | air sac |
| appendic/o | appendix |
| angi/o | vessel |
| arteri/o | artery |
| athr/o | joint |
| atri/o | atrium |
| audi/o | hearing |
| balan/ | glans penis |
| bio | life |
| bronch/i or broncho | bronchus |
| bronchiol/o | bronchiole |
| carcin/o | cancer |
| cardi/o | heart |
| cellul/o | cell |
| cerebell/o | cerebellum |
| cerebr/i or cerebro | cerebrum |
| chol/e | bile |
| cholecyst/o | gallbladder |
| choledoch/o | common bile duct |
| chondr/i or chondro | cartilage |
| chrom/o | color |
| col/o | colon |
| colp/o | vagina |
| cost/o | rib |
| cry/o | cold |
| crypt/o | hidden |
| cutane/o | skin |
| cyan/o | blue |
| cysti, cyst or cysto | bladder or cyst |
| cyt/o | cell |
| dipl/o | double or twice |
| duoden/o | duodenum |
| encephal/o | brain |
| enter/o | intestine |
| episi/o | vulva |
| erythr/o | red |
| esophag/o | esophagus |
| fibr/o | fibers |
| galact/o | milk |
| gastr/o | stomach |
| glyc/o | sugar |
| gynec/o | female |
| hemat/o | blood |
| hepat/o or hepatic/o | liver |
| heter/o | other or different |
| hidr/o | sweat |
| hist/o or histi/o | tissue |
| hom/o or home/o | same or alike |
| hydr/o | water or wet |
| hyster/o | uterus |
| latr/o | treatment |
| lle/o | lleum or intestine |
| lli/o | llium or pelvic bone |
| intestin/o | intestine |
| jejun/o | jejunum |
| kerat/o | cornea of eye or horny tissue |
| lacrima | tears |
| laryng/o | larynx |
| leuk/o | white |
| lipid/o | fat |
| lith/o | stone in gallbladder or kidney |
| lymph/o | lymph vessels |
| melan/o | black |
| men/o | menses or menstruation |
| mening/o | meninges |
| metra/a or metro | uterus |
| my/o | muscle |
| myel/o | bone marror or spinal cord |
| myring/o | eardrum |
| nat/o | birth |
| necr/o | death |
| nephr/o | kidney |
| neur/o | nerve |
| oophor/o | ovary |
| orchid/o or orchi/o | testis |
| oss/eo, ossi, ost, or osteo | bone |
| palat/o | roof of mouth |
| path/o | disease |
| peritone/o | peritoneum |
| pharmac/o | drug |
| pharyng/o | pharynx |
| phleb/o | vein |
| phren/o | diaphragm |
| pleur/o | pleura or side rib |
| pheum/a or pheumo | lungs |
| poli/o | gray matter of the nervous system |
| proct/o | rectum or anus |
| pulmon/o | lungs |
| py/o | pus |
| pyel/o | pelvis of kidney |
| rect/o | rectum |
| ren/i or reno | kidney |
| sarc/o | flesh |
| scapul/o | scapula |
| sept/o | infection |
| splen/o | spleen |
| spondyl/o | vertebra |
| stern/o | sternum |
| tend/o or teno | tendon |
| testicul/o | testis |
| therm/o | heat |
| thorac/o | chest |
| thym/o | thymus |
| thyr/o | thyroid gland |
| thyroid/o | thyroid gland |
| tonsill/o | tonsils |
| trache/o | trachea |
| tympan/o | eardrum |
| ur/e, urea, urin, urino, ur or uro | urine |
| ureter/o | ureter |
| urehtro/o | urethra |
| vas/o | vash deferens |
| vas/o or ven/o | vein |
| vesic/o | bladder |
| viscer/o | viscera |
| xanth/o | red or redress |
| xer/o | dry |
We’ve included a free printable version of the above list. Click here for our printable list of Interior Root Words. Once the list opens you will be able to print it.