Common Prefixes in Medical and Scientific Terminology

a-, an-

Without or not

ab-

Away from

ad-

Toward

ante-

Before, forward

anti-

Against

auto-

Self

bi-

Double, two

circum-

Around

contra-

Against, opposite

de-

Down, from, away from, not

dia-

Across, through, apart

dis-

Separation, away from

dys-

Bad, difficult, abnormal

ecto-

Outer, outside

en-

In, into, within

endo-

Inner, inside

epi-

Over, on

eryth-

Red

intro-

Into, within

leuk-

White

macro-

Large

mal-

Bad, illness, disease

mega-

Large

micro-

Small

mono-

One, single

neo-

New

non-

Not

para-

Abnormal

per-

By, through

peri-

Around

poly-

Many, much

post-

After, behind

pre-

Before, in front of, prior to

pro-

Before, in front of

re-

Again

retro-

Backward

ex-

Out, out of, from, away from

hemi-

Half

hyper-

Excessive, too much, high

hypo-

Under, decreased, less than normal

in-

In, into, within, not

inter-

Between

intra-

Within

semi-

Half

sub-

Under

super-

Above, over, excess

supra-

Above, over

trans-

Across

uni-

One