Word Building

There are a few word-building rules that can help either build or translate a new or unfamiliar term. (Remember, however, there are many exceptions to rules in constructing words.)

  1. The combining vowel is usually “o.” It is used to join word roots together to form a term.
    • Example: cardi/o/gram. When the second word begins with a vowel, as in the term gastr/ectomy, no joining vowel is used.
  2. Prefixes rarely are altered with a combining vowel to join to word roots.
    • Example: hyper/emesis, hyper/trophy
  3. Words are constructed in relation to the body’s structure. When more than one root appears in a word, they are connected in order from head to toe or from the inside organ outward.
    • Example: Gastr/o/intestine/al means pertaining to the stomach and intestine. Cephal/o/pelvic means pertaining to the head and pelvis. Ot/o/rhin/o/laryng/o/logist means one who studies the ear, nose, and throat.
  4. The root word is the foundation of the word.
    • Example: erythr/o/cyte
  5. A suffix used in a medical term usually describes a procedure or action. When attempting to translate a word, you should be able to begin at the end.
    • Example: cardi/o/logy means the study of the heart; proct/o/scop/y is the process of using an instrument to look into the anus.
  6. To make singular medical terms plural, you need to use different endings based on how the singular word ends. Table 4.1 lists some examples of singular and plural medical terms.
Table 4.1 Forming Plurals
Singular form Replace ending with Plural form
carcinoma -mata carcinomata
bacterium -a bacteria
corpus -i corpi
metastasis -ses metastases
coccus -i cocci
index -ices indices
amoeba -ae amoebae
thorax -aces thoraces
myopathy -ies myopathies
pelvis -es pelves