Medical Terminology
Building and Decoding Terms
Medical terminology is a system of word parts, not a vocabulary list. Every term is built from a root (the core meaning, often an organ or body part), a prefix (position, number, or rate), a suffix (procedure, condition, or specialty), and a combining vowel (usually o) that joins parts for pronunciation. Learn the parts and you can decode unfamiliar terms on the exam.
Concepts to Master
- Roots and combining forms: cardi/o (heart), gastr/o (stomach), nephr/o (kidney), hepat/o (liver).
- Prefixes: hyper- (above/high), hypo- (below/low), inter- (between), intra- (within), brady- (slow), tachy- (fast), dys- (difficult/painful), a-/an- (without).
- Suffixes: -itis (inflammation), -ology (study of), -ectomy (surgical removal), -otomy (incision), -ostomy (creating an opening), -algia (pain), -emia (blood condition), -plasty (repair).
- Plural rules: -a to -ae, -is to -es, -us to -i, -um to -a (diagnosis/diagnoses, appendix/appendices, bronchus/bronchi, datum/data).
- Common abbreviations and symbols that appear in orders and charts.
Traps
Questions often pair look-alike parts: hyper- versus hypo-, inter- versus intra-, and -ectomy versus -otomy versus -ostomy. Do not assume a combining vowel is always kept; it is usually dropped before a suffix beginning with a vowel. Abbreviations can be ambiguous (MS, PT), so read the context.
Worked Example
Break down gastrectomy: root gastr/o (stomach) plus suffix -ectomy (removal). The combining vowel is dropped before the vowel-initial suffix, giving “surgical removal of the stomach.” Rule of thumb: read the suffix first, then the prefix, then the root - that order usually reveals the meaning.