Medical Terminology — Word Parts Explained

Most medical words are assembled from up to four parts: a prefix at the start, a word root carrying the main meaning, a suffix at the end, and sometimes a combining vowel (usually "o") that links the parts so the word is easier to say. For example, "gastroenterology" is gastr (stomach) + enter (intestine) + -logy (study of).

The root is the core part that carries the meaning, such as "hepat" for liver. When a combining vowel — usually "o" — is added, it is called a combining form, such as "hepat/o". The vowel is a spoken bridge: it appears when the next part starts with a consonant (hepatology) and usually disappears before another vowel (hepatitis).

Medicine developed its shared vocabulary while Greek and Latin were the languages of science, and the words stuck because they are precise and understood internationally. Some concepts even have both a Greek and a Latin root — the kidney is "nephr" in Greek words (nephrology) and "ren" in Latin words (renal).

Learn the parts, not whole words. A few hundred prefixes, roots and suffixes unlock thousands of terms, because the same parts recombine everywhere. Start with the most common roots for each body system, add the condition and procedure suffixes, and practise by breaking real words into parts — every page in this section shows worked examples.

Position and job. A prefix goes first and adjusts the meaning — how much, where, when, or whether (hyper-, hypo-, pre-, post-). A suffix goes last and states what the word is — a condition (-itis), a procedure (-ectomy), a recording (-gram) or a specialist (-ologist). Reading a word from its suffix backwards is a reliable decoding trick.