For the health care professional, it is imperative that precision is used in the way patients’ physical conditions and diseases are described. Modern medical terms and terminology provides such precision and specificity. It facilitates effective communication and correspondence between physicians across borders and from different parts of the world. In addition, medical terminology is used in colleges of medicine and other areas of the health sciences.

A system of words, medical terminology can contain a prefix, root word, a combining vowel and a suffix to create medical terms. Medical terms describe medical aspects and diseases. Specific locations on the body are indicated by prefixes. The meanings of medical terms change with different beginnings and endings. Medical terms can contain multiple root words, combining vowels etc. A physician must be very precise when dictating a term. If a letter or word is misused or inadvertently changes, the result could be unnecessary tests and appointments. In addition, an unnecessary treatment or an incorrect diagnosis could occur. The rules that specify how the multitude of roots, prefixes, and suffixes can be combined are generally based in Latin.


Morphology of medical terms

Medical terms are created using root words with prefixes and suffixes that are Greek or Latin in origin. For example, “pericarditis” means “inflammation of the outer layer of the heart.” The three parts of this term are: peri – card – itis. The prefix is “peri” and means “surrounding”. The root word is “card” which means “heart”, and the suffix meaning of “itis” is “inflammation.” So, the term “pericarditis” can be translated to meaning an inflammation surrounding the heart.

By changing the prefix and suffix, the medical term can be used to describe a different heart condition. For example, “bradycardia” means slow heart rate. In this case, the three parts of this term are: brady – card – ia. The new prefix is “brady” which means “slow”. The new suffix is “ia” which is translated to “a condition or state”. So, the new meaning is “slow heart rate”.

Additional examples of how this medical term can change by changing the prefixes or suffixes are as follows:

Prefix changes:

myocarditis muscle layer of heart inflamed
pericarditis outer layer of heart inflamed
endocarditis inner layer of heart inflamed


Suffix changes:

cardiologist a physician specializing in the heart
cardiomyopathy damage to heart muscle layer
cardiomegaly enlargement of the heart

All medical terms must have at least one root word, but can have multiple. Also, medical terms can be without prefixes or suffixes. For example, the term “sternocleidomastoid” which is means a muscle with attachments at the sternum, the clavicle, and the mastoid. This medical term’s key parts are all roots: stern(root) – o – cleid(root) – o – mastoid(root). The vowel “o” appears between the roots and serve two purposes. They link the three roots, and they make the medical term easier to pronounce. Other vowels used for these purposes are “i” and “a”.medical terminology

Another example of how the vowel “o” links the different parts of a term is “electrocardiogram”. In this case, the parts are: electr – o – cardi -o -gram. Electr (electricity), o (vowel), cardi (heart), o (vowel), gram (suffix meaning record). So, the result is a medical term which means “the record of the electricity in the heart”.

Additional rules:

Generally, Latin prefixes go with Latin suffixes, while Greek prefixes go with Greek suffixes.

Prefixes generally end in vowels or vowel sounds as in the bradycardia example above.

Root words end in vowels. An example is the vowel “o” in the term “gastroenteritis”. The parts are: gastro(root) – enteritis(suffix). Gastroenteritis is an inflammation of the stomach and intestines.

Suffixes often refer to procedures, conditions, or disease processes. An example of a medical term with a suffix meaning that describes a condition is pancreatitis. The parts are “pancreas” which is the root, and then “itis” which is the suffix. Pancrea refers to the pancreas. “It is” refers the condition which is inflammation.


A brief history of medical terms

Medical terminology originated during the Renaissance when the discipline of anatomy begun. Practicing in Italian medical schools, early anatomists and physicians used Latin to describe various parts of the anatomy. These naming conventions have remained in place to current day. One such physician was Galen (a. d. 130-200) who authored early medical texts and was responsible for many terms. Other sources of medical terminology include:

Arabic- throughout the middle ages, Arabic scholars had taught medicine and originated many terms.

English- medical terminology has roots in the English language which has been pre-eminent in biomedical science over the last 50 years.

Biology- is a prominent source of medical terminology going back to Carl Linnaeus (1707–1778). Linnaeus was a Swedish botanist and physician who is considered the father of modern taxonomy. He developed a binomial nomenclature which is the modern system of naming organisms. Much of his work was done in Latin.


Learning medical terms:

While proficiency in Latin is not required to learn medical terminology or to become a physician, it is certainly useful to grasp the nuances of the medical terms. However, more important than learning Latin, is learning common root words, prefixes, and suffixes.

Following are some of the most frequently used prefixes and suffixes in medical terminology. Memorizing these will jumpstart your learning of the medical terms. This small group of prefixes and suffixes will help with the interpretation of the larger body of medical terms. You don’t need to know whether they are prefixes or suffixes and you don’t need to know Latin.

Prefix/Suffix: Equals: Examples:
a/an Without or none anemia
ectomy to cut out or remove appendectomy, tonsillectomy
gram the image (X-ray) mammogram
graphy/ graph recording an image (X-ray, CT or MRI scan or a written recording) mammography (imaging the breasts)
itis inflammation tonsillitis, appendicitis
macro large macrostomia (abnormally large mouth)
mega/ megaly enlarged megacolon (abnormally large colon large intestine)
micro small microstomia (abnormally small mouth)
osis abnormal condition cyanosis (of blueness, due to cold or low oxygen)
ostomy to make a “mouth” colostomy (to make a permanent opening in colon)
otomy to cut into tracheotomy (to cut into the windpipe, temporary opening)
scopy/ scopic to look, observe colonoscopy (look into colon)


Medical term tools and resources

As with any discipline, practice using medical terminology is required to achieve full proficiency. Following are practice materials and resources design to build proficiencies in medical terminology:

Medical Terminology Exams – Test your command of medical terminology with this battery of 20 medical exams.

Word Building Reference:  This reference tool demonstrates how various prefixes, suffixes and root words are used to create medical terms. It will strengthen your understanding of medical terminology.

Medical Terms – Singular versus plural rules: this resource describes the grammatical rules that specify how to use the singular vs. plural versions of terms. For example, for terms that end in “a”, for plural add an “e”. In this case, the term vertebra (singular), would be vertebrae (plural).

Alphabetical list of medical terms– this is a comprehensive and alphabetical list of medical terms with each term broken down by prefix, root and suffix. Click on any of the letters below to go to the terms beginning with that letter:

Alphabetical Listing of Med Terms



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