Medical Prefixes

a, or an

without; absent; negative; not

mega/megaly

great; big; enlarged

ab or abs

away from

men/o

menstrual; monthly

alg/i

pain

meta

beyond; over; change

amb/i

on both sides

micro

small

ante

before

mono

single

anti

against

myel

marrow

auto

self

olig/o

less than normal, scanty, few

bi

two or both

os

mouth or opening

brachi

short

para

along side of

brady

slow

part

bear, give birth

circum

around

path

sickness, disease

contra

against; opposed

per

excessive

demi

half

peri

around (or outer)

de

from

poly

many; much

di

double; apart from

post

after

dys

difficult; painful; abnormal

noct

night

en

in

pre

before

endo

within or inside of

psued/o

false

epi

upon, on top

py/o

pus

exo

out

retr/o

back, behind

fore

in front of

semi

half

hem/o

blood

sub

under

hemi

half

supra

above; greater

hom/o

same or similar

syn

with; together

hydro

water

tach/y

fast

hyper

above, high; excessive

toc

childbirth

hypo

below, low; deficient

thrombo

lump; clot

infra

beneath

trans

across or through

inter

between

intra

within

is/o

equal

kera

hard

kinesi

movement

later/o

side

lith/o

stone; a stone

macr/o

large

mal

bad, poor

medi

middle