Medical Roots, Prefixes & Suffixes

MedicalPhysicist’s index includes 750 common roots, prefixes, and suffixes. When available, the original Greek or Latin term is provided in parentheses after the English definition.

Medical Word Parts

Three standard word elements—roots, prefixes, and suffixes—are used to construct most medical terms. The definition of each term is drawn from the meaning of its constituent parts. By recognizing common word parts and their meanings, you'll be able to decipher the definitions of hundreds of medical terms.

  • Prefix: When included, the prefix appears at the beginning of a medical term. It usually indicates a location, direction, type, quality, or quantity.
  • Root: The root gives a term its essential meaning. Nearly all medical terms contain at least one root. A vowel (usually the letter “o”) may be added to the root to aid in pronunciation. Together, the root and vowel are called the combining form.
  • Suffix: The suffix appears at the end of a term and may indicate a specialty, test, procedure, function, disorder, or status. Otherwise, it may define whether the word is a noun, verb, or adjective.

For more on medical terminology, see MedicalPhysicist's Introduction to Medical Terminology.