The Big Picture
Medical terms often contain smaller word parts joined together. Each part adds meaning to the finished term.
Some medical terms use only a root and another word element. Others contain several parts. The most important placement rule is simple: prefixes always come before roots, and suffixes always come after roots.
Start Here If You’re Overwhelmed
Focus on these core ideas:
- A word element is a part of a word.
- A root word contains the basic meaning of the word.
- A prefix comes at the beginning of a word and changes its meaning.
- A suffix comes at the end of a root and changes its meaning.
- Prefixes always come before roots.
- Suffixes always come after roots.
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Course Notes: Key Ideas You Need to Know
What Is a Word Element?
A word element is a part of a word. Medical terms form when different word elements join together.
The main word elements in these examples are roots, prefixes, and suffixes.
Root Words
A root word is the word element that contains the basic meaning of the word.
A root may join with:
- a prefix
- another root
- a suffix
Roots provide the reference point for these placement rules. Prefixes always come before roots, while suffixes always come after roots.
Prefixes
A prefix is a word element placed at the beginning of a word to change its meaning.
For example:
- dys means difficult.
- pnea is the root meaning breathing.
- dys + pnea forms dyspnea.
- Dyspnea means difficulty in breathing.
Suffixes
A suffix is a word element placed at the end of a root to change its meaning.
For example:
- mast is the root meaning breast.
- ectomy is the suffix meaning excision or removal.
- mast + ectomy forms mastectomy.
- Mastectomy means removal of a breast.
A Prefix, Root, and Suffix Together
Some medical terms contain all three major word elements.
Endocarditis contains:
- endo, a prefix meaning inner
- card, a root meaning heart
- itis, a suffix meaning inflammation
Together, these word elements form endocarditis, meaning inflammation of the inner part of the heart.
More Complex Combinations
Medical terms may contain several word elements. More complex combinations include:
- two prefixes, a root, and a suffix
- a prefix, two roots, and a suffix
- two roots and a suffix
The number of word elements may change, but their placement rules stay the same.
The Two Placement Rules to Remember
Two rules help you recognize how medical terms are built:
- Prefixes always come before roots.
- Suffixes always come after roots.
These rules still apply when a medical term contains several prefixes, roots, or suffixes.
Exam Clue Words
- Always: A prefix always appears before a root.
- Always: A suffix always appears after a root.
The word always makes these placement rules definite. The position of the prefix or suffix does not change when more word elements appear in the term.
Fast Review
Medical terms form by joining word elements. Focus on what each element means and where it belongs.
- A word element is a part of a word.
- A root word contains the basic meaning of the word.
- A prefix appears at the beginning and changes the word’s meaning.
- A suffix appears at the end of a root and changes the word’s meaning.
- dys + pnea forms dyspnea, meaning difficulty in breathing.
- mast + ectomy forms mastectomy, meaning removal of a breast.
- endo + card + itis forms endocarditis, meaning inflammation of the inner part of the heart.
- Medical terms may contain more than one prefix or root.
- Prefixes always come before roots.
- Suffixes always come after roots.
Final Pep Talk
Medical terms may look long at first, but you do not need to treat the whole term as one piece. Focus on the word elements, their meanings, and the two placement rules as you review.