Skip to main content
Back

Medical Terminology: Understanding Prefixes

NotesPracticeVideo lessons

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Prefixes in Medical Terminology

Prefixes are essential components in medical terminology, providing information about numbers, amounts, qualities, and positions. Understanding these prefixes helps in deciphering complex medical terms and enhances communication in healthcare settings.

Prefixes Indicating Numbers and Amounts

These prefixes specify details about numbers, sizes, or amounts in medical terms.

Prefix

Definition

Example/Memory Tool

ambi-

both

ambidextrous

centi-

1/100

centimeter

di-

two

diplopia (double vision)

milli-

1/1000

millipede

mono-, uni-

one

monocular

multi-, poly-

many, much

multicultural, polyuria

nulli-

none

null and void

semi-, hemi-

half

semicircle, hemisphere

  • Example: The term polyotia means having more than two ears (poly- = many, otia = ears).

Prefixes Indicating Quality

These prefixes modify the meaning of a word to describe a particular attribute, difficulty, or characteristic, often relating to the degree, nature, or quality of a condition.

Prefix

Definition

Example/Memory Tool

brady-

slow

bradycardia (slow heart rate)

dys-

difficult, bad, painful

dysuria (painful urination)

eu-

good

euphoria

hetero-

different

heterogeneous

mal-

bad

malfunction

mega-, megalo-

very large

megaphone, megaloblast

tachy-

rapid, fast

tachycardia (fast heart rate)

ultra-

beyond normal

ultrasound, ultra-fast

  • Example: Megalocephaly refers to an abnormally large head size (megalo- = very large, cephaly = head).

  • Practice: Dyspnea means difficulty breathing (dys- = difficult, -pnea = breathing).

Prefixes Indicating Position and Placement

These prefixes specify a location, direction, or spatial relationship in medical terms.

Prefix

Definition

Example/Memory Tool

ante-, pre-, pro-

in front of

anterior, preoperative, prognosis

dors-, dorso-

back

dorsal

epi-, supra-

over, above, on top of

epidermis, suprarenal

peri-

surrounding

pericardium

ab-

away from

abduction

ad-

towards

adduction

ecto-, exo-

outside, out of

ectoderm, exocrine

endo-, intra-

within

endoscope, intracellular

para-

beside

paralegal, parathyroid

dia-

through

dialysis

  • Example: Hypothermia means below normal body temperature (hypo- = below, thermia = temperature).

Application and Practice Questions

  • Polyneuritis: Inflammation affecting many (poly-) nerves (neur-) leading to problems with vision.

  • Hypodermatitis: Inflammation of the skin (dermat-) below (hypo-) the dermis.

  • Excision: The process of cutting out (ex- = out, -cision = cutting).

Additional Info

  • Prefixes are combined with root words and suffixes to form complete medical terms.

  • Understanding the meaning of prefixes can help deduce the meaning of unfamiliar medical terms.

Pearson Logo

Study Prep