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2.5 Prefixes

A prefix is located at the beginning of a medical term and alters the meaning of the term. It is important to spell and pronounce prefixes correctly. When writing a prefix, if it is not in a medical term, you must place a “-” after the prefix. Not all medical terms have a prefix, but many do.

The following is a good technique to help you memorize prefixes:

  • Start by reviewing the most common prefixes that are listed below.
  • Compare the prefixes to the examples of use in medical terms in the tables below.
  • Try to relate the prefixes to common terms you hear in everyday life.
Table 2.6 Prefixes 
Prefixes MEANING EXAMPLE OF USE IN MEDICAL TERMS
a- , an- no, not asepsis
ab- away from abduction
ad- toward adduction
ante- before antepartum
anti- against antigen
bi- both sides bilateral hip reconstruction
cata- down, complete cataplasia
circum- around circumcision
dia- through, complete diarrhea
dis- apart, away dislocation
dys- painful dysentery
ec- out, outside of ectopic pregnancy 
endo- , en- within endoscope
exo- outside exocrine

 

normal pregnancy location in the uterus compared to ectopic pregnancy in the ovary, abdomen or fallopian tubes
Figure 2.7

Key Concept

An ectopic pregnancy is medical emergency and must be treated as soon as possible because of the potential medical consequences if it is not. Figure 2.7 illustrates the location of the embryo in a normal pregnancy and in an ectopic one; an ectopic pregnancy can occur in the ovaries, fallopian tubes, cervix, or abdomen. The term ectopic has the prefix ec-, meaning “outside of,” top meaning “place,” and -ic, meaning “pertaining to.”

Table 2.7. Prefixes 
Prefixes MEANING EXAMPLE OF USE IN MEDICAL TERMS
hemi- half hemigastrectomy
hyper- too much, excessive hypertension
hypo- too little, less than normal hypotension
inter- between intercostal
intra- within intravenous
meta- change, beyond metacarpal
neo- new neonatal
para- beside, near parathyroidectomy
peri- around pericardial
post- after postpartum
pre- before preoperative
sub- under, beneath subcutaneous
supra- above suprapubic
trans- across, through transurethral

 

Benign prostatic hyperplasia with an enlarged prostate compared to normal sized prostate
Figure 2.8

Key Concept

Figure 2.8 illustrates the difference between a normal prostate and an enlarged one caused by benign prostatic hyperplasia. This term includes the prefix hyper-, meaning “excessive,” which relates to the increase in the size of the prostate.

This condition is often treated with medication or through a procedure called a transurethral resection of the prostate. Transurethral has the prefix trans-, meaning “across or through,” urethro, meaning “urethra,” and -al meaning “pertaining to.” As the meaning of this medical term indicates, it is a procedure where part of the prostate is removed with a surgical instrument that goes through the urethra.

 

Attribution

Unless otherwise indicated, material on this page has been adapted from the following resource:

Sturdy, L., & Erickson, S. (2022). The language of medical terminology. Open Education Alberta. https://pressbooks.openeducationalberta.ca/medicalterminology/, licensed under CC BY-NC-SA 4.0

 

Image Credits

(Images are listed in order of appearance)

Ectopic Pregnancy by BruceBlaus, CC BY-SA 4.0

Benign Prostatic Hyperplasia (BPH) by BruceBlaus, CC BY-SA 4.0

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Introduction to Reprocessing Copyright © 2025 by NorQuest College is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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