Medical Terminology: Chapter 3 Prefixes

Characteristics of Prefixes

  • Definition: A word element placed at the beginning of a word that changes its meaning.

  • Occurrence: Prefixes are not contained in all medical terms.

  • Similarity: Most prefixes are the same as those used in common English language.

  • Source material: Based on Medical Terminology Systems, Ninth Edition by Regina M. Masters, Barbara A. Gylys, and Mary Ellen Wedding from F.A. Davis Company (Copyright ©2026).

Prefixes of Position

  • epi-: above, upon (example: epi/gastr/ic).

  • inter-: between (example: inter/cost/al).

  • pre-, pro-: before, in front of (example: pre/nat/al).

  • post-: after, behind (example: post/nat/al).

  • sub-, infra-, hypo-: under, below, deficient (example: sub/nas/al, hypo/derm/ic).

  • retro-: backward, behind (example: retro/version).

Prefixes of Number and Measurement

  • nulli-: none.

  • primi-: first.

  • mono-, uni-: one (example: uni/nucle/ar).

  • bi-, di-: two (example: bi/later/al).

  • dipl-, diplo-: double (example: dipl/opia).

  • tri-: three (example: tri/ceps).

  • quadri-: four (example: quadri/plegia).

  • hemi-, semi-: one-half (example: hemi/plegia).

  • multi-, poly-: many, much (example: poly/phobia).

  • macro-: large (example: macro/cyte).

  • micro-: small (example: micro/cyte, micro/scope).

Prefixes of Direction

  • ab-: from, away from.

  • ad-: toward.

  • circum-, peri-: around (example: circum/ren/al).

  • dia-, trans-: through, across (example: dia/rrhea).

  • endo-, intra-: in, within (example: endo/crine, intra/muscul/ar).

  • ecto-, exo-, extra-: outside, outward (example: extra/crani/al).

  • super-, supra-: upper, above, excessive, superior (example: supra/ren/al).

  • brady-: slow (example: brady/cardia).

  • tachy-: rapid (example: tachy/pnea).

  • hetero-: different.

  • pseudo-: false (example: pseudo/cyesis).

Common Qualitative Prefixes

  • a-, an-: without, not (example: a/mast/ia, an/esthesia).

  • anti-, contra-: against (example: anti/bacteri/al).

  • dys-: bad, painful, difficult (example: dys/pnea, dys/tocia).

  • eu-: good, normal (example: eu/pnea).

  • mal-: bad.

  • homo-, homeo-: same (example: homo/graft).

  • syn-: union, together, joined.