Prefixes

The ability to break down medical terms into separate components or to recognize a complete word depends on the mastery of the combining forms (a stem or root with an "o" attached), roots or stems that appear in medical terms, and prefixes and suffixes that alter or modify meaning and usage of a term.

Prefixes, the most frequently used elements in the formation of Greek and Latin words, consist of one or more syllables (prepositions or adverbs) placed before words or roots to show various kinds of relationships. They are never used independently, but when added before verbs, adjectives, or nouns, they modify the meaning. Most prefixes are a part of words in ordinary speech and do not refer specifically to medical or scientific terminology, but many occur frequently in medical terminology. The prefixes used in medical terminology follow.

Prefix	Meaning	Examples
a-, an-	Without, not lack of	Aphasia (without speech) Anemia (lack of blood)
ab-ab-	Away from	Abductor (leading away from) Aboral (away from mouth)
ad-	To, toward, near	Adductor (leading toward) Adrenal (near the kidney)
ambi-, ampho-	Both	Ambidextrous (ability to use hands equally) Amphogenic (producing young both sexes)
amphi-	On both sides, double	Amphibious (living both on land and in water) Amphithymia (dual mental state of depression and elation)
ana-	Up, toward, apart	Anatomy (to cut apart) Anacatharis (vomiting up)
ante-	Before, in front of, forward	Antecubital (before elbow) Anteflex (to bend forward)
anti-	Against, opposing	Anticarious (against cavities) Antisepsis (against infection)
ap-, apo-	Separation from, derived from	Apobiosis (death of a part) Apocleisis (aversion to food)
aut-, auto-	Self	Autoanalysis (self analysis) Autoerotism (sexual self love)
bi-	Two, double, twice	Biarticulate (double joint) Bifocal (two foci)
cata-	Down, under, lower, against	Catabolism (breaking down) Catalepsy (reduced movement)
circum-	Around	Circumflex (winding around) Circumarticular (around joint)
co-, * com-, Ü con-	With, together	Commissure (coming together) Conductor (leading together)
contra-	Opposed, against	Contralateral (opposite side) Contraception (prevention of conception)
de-	Down, from	Dehydrate (remove water from) Decay (break down)
di-	Two, twice	Dicephalous (two headed) Dichromic (having two colors)
dia-	Between, through, apart, across, completely	Diaphragm (wall across) Diapedesis (ooze through) Diagnosis (complete knowledge)
dis-	Apart or free from	Disinfection (infection) Disarticulation (separation at a joint) Dissect (cut apart)
dys-	Difficult, bad, painful	Dyskinesis (difficult motion) Dyspepsia (bad digestion) Dyspareunia (painful coitus)
e-, ec-, ex-	Out of, from, away from	Enucleate (remove whole from) Exostosis (outgrowth of bone) Ectopic (out of place) Ectal (on the surface)
ect-, ecto-, exo-	Outer, outside, situated on	Ectoderm (outer skin) Ectocystic (outside of cell) Exogenic (originating outside)
em-, ** en-	In	Empyema (pus in) Encranial (in the cranium)
end-, endo-, ent-, ento-	Within, inner	Endaural (within the ear) Endocranial (within cranium) Entiris (inner eye color) Entocele (internal hernia)
ep-, epi-	Upon, on, over	Epicostal (upon a rib) Epidermis (outer skin layer) Eponychia (infection over the nail bed)
eu-	Normal, good, well, healthy	Eucrasia (normal health) Eublastic (healing well)
extra-, extro-	Outside of, beyond, outward	Extraoral (outside of mouth) Extroversion (turning inside out)
hemi-	Half	Hemiepilepsy (epilepsy on one side of body) Hemilingual (half of tongue)
hyper-	Excessive, above, beyond	Hyperactive (overactive) Hypertension (above normal blood pressure)
hyp-, hypo-	Under, deficient, beneath	Hypalgia (reduced pain sense) Hypothyroidism (deficiency of thyroid activity)
im-, ÜÜ in-	In, into, within	Implant (insert into) Injection (forcing fluid into)
im-, Ü in-	Not	Immature (not mature) Involuntary (not voluntary)
infra-	Below, beneath	Infraorbital (beneath eye) Infracostal (below a rib)
inter-	Between	Intercostal (between ribs) Internodal (between nodes)
intra-	Within	Intracardiac (within heart) Intraocular (within the eye)
intro-	Into, within	Introversion (turning inward) Introrsus (turned in)
mes-, meso-	Middle	Mesencephalon (midbrain) Mesonasal (middle of nose)
meta-	Change, beyond	Metachrosis (color change) Metabasis (disease changes)
micr-, micro-	Small	Micracoustic (faint sounds) Microbe (minute organism)
mult-, multi-	Many	Multiangular (many angles) Multiform (many shapes)
neo-	New, recent	Neoblastic (new tissue growth) Neonatal (newborn)
pan-	All, entire	Panacea (cure-all) Pantalgia (entire body pain)
para-	Beside, beyond, after	Paracardiac (beside the heart) Paracyesis (pregnancy outside the uterus)
per-	Through, excessive	Permeable (may pass through) Peracute (excessively sharp)
peri-	Around	Periosteum (around bone) Peribulbar (around eye bulb)
poly-	Many, much, excessive	Polycystic (many cysts) Polydipsia (excessive thirst)
post-	After, behind	Postoperative (after surgery) Postocular (behind eye)
pre-, pro-	Before, in front of	Prenatal (before birth) Project (throw forward)
pseud-, pseudo-	False	Pseudarthrosis (false joint) Pseudocyesis (false pregnancy)
re-	Again, backward	Reflex (bend back) Regurgitation (vomiting)
retro-	Backward, behind	Retrograde (going backward) Retrolingual (behind tongue)
semi-	Half	Semiconscious (partly aware) Seminormal (half normal)
sub-	Under, beneath	Subcutaneous (under the skin) Subungual (under the nail)
super-, supra-	Above, superior, excess	Superactivity (overactivity) Suprarenal (above kidneys)
sym-, ** syn-	Together, with	Symmelia (fusion of limbs) Synclinal (bent together)
trans-	Across, through	Transection (cut across) Transaortic (through aorta)
ultra-	Beyond, excess	Ultravirus (very small virus) Ultrasonic (beyond upper limit of human hearing)

* co-	before a vowel	Ü com-	before b, m, and p
** em-	before b, m, and p	ÜÜ im-	before b, m, and p
*** sym-	before b, m, p, and ph

REFERENCE

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