Introduction / Warning

The starting point for this website (Medical Abbreviations - Always Current) is the book authored by Dr. Neil M Davis, titled, Medical Abbreviations: 55,000 Conveniences at the Expense of Communication and Safety, 16th ed., 2020. New acronyms, symbols, abbreviations, drug names, and even some slang terms are continuously added and the totals are found at the bottom of each page. This constantly growing database is being compiled to assist individuals in understanding and transcribing medical, nursing, pharmaceutical, and other health-related communications and documents. Your suggestions and comments are welcomed.


Abbreviations are a convenience, a time saver, a space saver, a way of fitting a word or phrase into a restricted space on a form or computer, and a way of avoiding the possibility of misspelling words. However, a price can be paid for their use. Abbreviations are sometimes not understood, misread, or are interpreted incorrectly. Their use lengthens the time needed to train individuals in the health fields, wastes the time of healthcare workers in tracking down their meaning, at times delays the patient's care, and occasionally results in patient harm.

The publication of a term on this website is NOT an endorsement of its legitimacy. It is not a guarantee that the intended meaning has been correctly captured, or an indication that they are in common use. The person who uses an abbreviation must take responsibility for making sure that it is properly interpreted. When an uncommon or ambiguous abbreviation is used and there is a possibility that it may not be understood correctly, it should be defined by the writer. Where uncertainty exists, the one who wrote the abbreviation must be contacted for clarification.

Types of Medical Abbreviations found on

There are three types of what are generally termed as abbreviations:

  1. Acronyms:  Lettered abbreviations which are pronounced as a word (e.g, AIDS)
  2. Initialism:  First letter of each word is used and it is not pronounced as a word (e.g, HIV)
  3. Brief Form:  A shortened form of a word (e.g, exam vs. examination)

This site also includes both generic brand name drugs.

Notes on Medical Abbreviations

A few words from Neil M. Davis, MS, PharmD, FASHP:

Lower case letters are used when firm custom dictates as in Ag, Na, mCi, etc. The first letter of brand names are capitalized, whereas non-proprietary names appear in lower case.

Some abbreviations which have been encountered or that have been suggested for addition to this website have not been added. Some were obscene or completely insensitive.

Drug name abbreviations are shown for informational purposes and should not be used as they may not be recognized or properly identified. Some have been marked as dangerous abbreviations; this is arbitrary, as all of the drug name abbreviations could be marked as dangerous.

Abbreviations for medical facility names create problems as they are often not recognized by an individual in other geographic areas reviewing that information. A clue to the fact that one is dealing with such an abbreviation is when it ends with MC, for Medical Center; HS, for Health System; MH, for Memorial Hospital; CH, for Community Hospital; UH, for University Hospital; and H, for Hospital. These are not usually added to MedAbbrev.

The use of abbreviations are not uniform across the country, and usage tends to cluster. Sometimes physicians just make up their own abbreviations. Sometimes a physician-in-training will pick up and use abbreviations used by residents or attendings where they train. Sometimes group practices will start to use certain abbreviations. Sometimes organizations might have banned certain abbreviations, so you might not see them used at one location, while at another location they are used. Usage will also vary by specialty.

Form designers and computer programmers should be sensitive to the fact that unrealistic restriction of space for entering data can cause users to create abbreviations which will be unfamiliar to individuals reviewing the record at a later date.

As in the medical and other scientific literature, organism and plant names, and non-English words and abbreviations are expressed in italics on this website; however, in the medical transcription field, these are expressed in normal typeface1. It also should be noted that in computerized health records, italics, boldface type, superscripts, and subscripts are often expressed in normal typeface.

This Website

When an abbreviation which ends with "s" cannot be found it might be a plural form of a listed abbreviation. When an abbreviation cannot be found on this website or when the listed meaning(s) do not make sense, there is a possibility that the abbreviation has been misread. As an example, one individual could not find the meaning of HHTS. On closer examination, it really was +HTS, not HHTS. Also, EWT could not be identified because it was really ENT. It should be noted that some common French and Spanish abbreviations are included on this website. Because of language structure differences, abbreviations are often reversed, as in the case of HIV, which in Spanish and French is abbreviated as VIH.

The Primer page presents a list of 300 of the most commonly used abbreviations. The purpose of this list is to serve as a beginning point or primer for those entering a health-related field.

This website also contains thousands of drug names (generic and brand names) which includes both commonly prescribed drugs as well as new drugs. Brand names have their first letter capitalized whereas generic names are in lower case. The inclusion of these terms enables the searcher to obtain the generic name for brand name products or brand names for generic names. Clicking words in the search result link to drug information found on Wikipedia.

Use of Abbreviations

Avoid using abbreviations when naming a diagnosis and/or operative procedures. These are critical points of information, and their meanings must be clear to assure accurate communication for patient care, reimbursement, statistical purposes, and medicolegal documentation.

Although recommended by many style manuals, by custom, and shown on this website, the use of italics, boldface, superscripts, and subscripts are not always employed in documentation because of the extra effort/time necessary to produce them, and they can be misinterpreted.

The Council of Biological Editors (CBE), in their 1983 edition of the CBE Style Manual listed about 600 abbreviations gathered form 15 internationally recognized authorities and organizations.2 The majority of these symbols and abbreviations tend to be more scientifically oriented than those which would appear in medical records. In the few situations where the CBE abbreviations differ from what is presented on this website, the CBE abbreviation has been placed in parentheses after the meaning. As is the practice in the United States, mL has been used rather than ml and the spelling of liter, meter, etc. is used rather than litre and metre, even though ml, litre and metre are listed in the CBE Style Manual. A current edition of the CBE Style Manual was published in 2006.3 Again, in that edition, emphasis is placed on scientific abbreviations.

Only a few of the acronyms and abbreviations for the major cardiologic trials, such as, TIMI - Thrombosis In Myocardial Infarction (trial), have been included in this website. For a list of 4,200 of these acronyms and abbreviations, consult reference number 3 .

Time will tell what effect the texting generation will have on the appearance of new abbreviations in medically-related documents. Some have been added to MedAbbrev such as “AOK” for “all is okay.”

Over the years certain abbreviations are no longer used because of changes and/or advancements. These obsolete abbreviations are not removed from this website because old records are often reviewed for auditing, research, and medicolegal sleuthing. Secondly, some physicians are slow to let go of out-of-date terminology or abbreviations and will likely use early-learned abbreviations out of habit, perhaps for a lifetime.


On the positive side, the use of abbreviations:

On the negative side, will this uncontrolled use of abbreviations result in:

An examination of the sheer number of abbreviations, acronyms, and symbols is a testimonial to the problems and dangers associated with uncontrolled use of undefined abbreviations.


  1. CBE Style Manual, 5th ed. Bethesda, MD; Council of Biology Editors; 1983.
  2. Council of Science Editors, Style Manual Committee, Science style and format: the CSE Manual for authors, editors, and publishers. 7th ed. Reston (VA):The Council; 2006.
  3. Cheng TO, Julian D. Acronyms of cardiologic trials - 2002. Int J Cardiol 2003;91:261-351.

  4. If you encounter abbreviations which are not in this website, please send them to us.

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