Learn the main components of medical terms. To comprehend how to use combining values in medical terminology, it is first necessary to understand medical term parts.
Root: Foundational base of a medical term, where the meaning of the term can be found.
Prefix: Word part that modifies the meaning of the medical term. This is often an indication of direction, time or orientation.
Suffix: An ending that modifies the root of the medical term and indicates a normal or pathological condition or procedure.
Combining Vowel: A letter used to ease pronunciation and that connects either two roots or a root and suffix.
Combining form: The combination of the root word and combining vowel.
Insert combining vowel between the roots if the first root ends with a consonant and second root begins with a consonant. For example, the combination of stern/o +cleid /o +mastoid is three root words combined to describe a muscle used for turning the head that is attached to the sternum (chestbone in Greek), the clavicle (clavis key in Latin), and the mastoid (breast-shaped in Greek).
Join combining form and suffix if the the first root ends with a vowel and the second root begins with a vowel. For example, in the combination of oste/o+cyte, osteo, the combining form of oste (bone in Greek) joins with cyte (kytos, cell in Greek) to create the word "bone cell."
Study the vowel conditions. The most common combining vowel is "o"; however, "i" is also a combining vowel used in medical terminology. If both roots are Latin, then "i" may be the combining vowel in rare cases. For example, Quadr/i-cep contains the root quadr (quattuor in Latin is four), the combining vowel "i," and cep (caput is head in Latin) to form quadriceps to mean the thigh muscle with four heads. The most frequent combining vowel "o" can be used if roots are Latin and Greek, both Greek or both Latin.
Memorize the rules regarding the exceptional cases where combining vowels are not employed. A combining vowel is not used before a suffix that begins with a vowel.
For example, Hypo+insulin+emia has the prefix hypo (low) attached to the beginning of insulin (root) and the suffix emia (blood) is added at the end. No combining vowel is added, because the prefix ends in a vowel and the suffix starts with a vowel. If the root ends in a vowel and the suffix begins with the same vowel, drop the final vowel from the root and do not use a combining vowel. For example, Cardi+itis becomes carditis, meaning inflammation of the heart.