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The starting point for this website was the book authored by Dr. Neil M Davis titled. Medical Abbreviations: 32,000 Conveniences at the Expense of Communication and Safety, 15th ed., published, January 2011. Over 50 new entries are added each week so that as of March 2014, has been updated with 10,200 new entries since the book was published. As of March 2014, medabbrev. com listed over 42,200 possible meanings of acronyms, symbols, abbreviations, and slang terms. This constantly growing list is being compiled to assist individuals in understanding and transcribing medical, nursing, pharmaceutical, and other health-related communications and documents.

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 this list of abbreviations is not an endorsement of their 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 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.

   There are three types of what are generally termed as abbreviations:
   • Acronyms: Lettered abbreviations which are pronounced as a word (e.g, AIDS)
   • Initialism: First letter of each word is used and it is not pronounced as a word (e.g, HIV)
   • Brief Form: A shorten form of a word (e.g, exam)

   There are many variations in how an abbreviation can be expressed. Anterior-posterior has been written as AP, A.P., ap, and A/P. Since there are few standards and those who use abbreviations do not necessarily follow these standards, this book only shows anterior-posterior as AP. This is done to make it easier to find the meaning of an abbreviation as all the meanings of AP are listed together. This elimination of unnecessary duplication also keeps the book at a convenient size, thus enabling it to be sold at a reasonable price.

   When an abbreviation is made up of a series of abbreviations, it may not be listed as such. In such instances, the meaning may be determined by looking up each set of abbreviations, as in the example of DTPa-HIB-PNU-MEN, which means, diphtheria, tetanus toxoids, acellular pertussis; Haemophilus influenzae type b conjugate; pneumococcal (Streptococcus pneumoniae) conjugate; meningococcal (Neisseria meningitidis) conjugate (serogroups unspecified) vaccine.

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

   The abbreviation AP is listed as meaning doxorubicin and cisplatin. The reason for this apparent disparity is that the official generic names (United States Adopted Names) are shown rather than the brand names Adriamycin and Platinol. In the case of LSD, the official name, lysergide, is given, rather than the chemical name, lysergic acid diethylamide. The Latin derivations for older medical and pharmaceutical abbreviations (t.i.d., ter in die, three times daily) may be found in Remington.1

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

   Abbreviations for medical facility names create problems as they are usually not recognized by the readers in other goegraphic areas. 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.

   The use of abbreviations are not uniform across the country, and usage tends to cluster. Somtimes 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 hospitals might have banned certain abbreviations, so you might not see them used at one hospital, while at another hospital they are used. Usage will also vary by specialty.

   Form designers and computer programers 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 future readers.

   As in the medical and other scientific literature, organism and plant names, and non-English words and abbreviations are expressed in italics in this this book and Internet version, however in the medical transcription field, these are expressed in normal typeface2. It also should be noted that in computerized health records, italics, boldface type, superscripts, and subscripts are expressed in normal typeface.

   When an abbreviation which ends with "s" can not be found it might be a plural form of a listed abbreviation. When an abbreviation cannot be found in this book or when the listed meaning(s) do not make sense, there is a possibility that the abbreviation has been misread. As an example, a reader 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. Some common French and Spanish abbreviations are listed in the book. 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 presents a list of 275 of the most commonly used abbreviations. The purpose of this list is to serve as a primer for those entering a health-related field.

   Drug Search contains a cross-referenced list of 3,400 generic and brand drug names. The list contains names of commonly prescribed and new drugs.Brand names have their first letter capitalized whereas generic names are in lower case. This list will enable readers to obtain the generic name for brand name products or brand names for generic names. It will also serve as a spelling check.

   Coded drug names and abbreviations for drug names are found in the abbreviation search.

   National Laboratory Values is a table of normal laboratory values. Both the conventional and international values are listed. Each laboratory publishes a list of its normal values. These local lists should be reviewed to see if there are significant differences.

   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, statical purposes, and medicolegal documention.

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

   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.3 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 in this book, 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 mtere are listed in the CBE Style Manual. A current edition of the CBE Style Manual was published in 2006.4 Again, in this 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 book. For a list of 4,200 of these acronyms and abbreviations, consult reference number 5.

   For a more complete list of abbreviations used for cancer chemotherapy protocols see the appendix of the reference book/web-version, Drug Facts and Comparisons.5

   Time will tell what affect the texting generation will have on the appearance of new abbreviations in medically-related documents.

   Over the years certain abbreviations are no longer used because of changes and/or advancements. These obsolete abbreviations are not removed from this book because old records are 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. Since the purpose of the book is to help readers decipher whatever it is that they are reading, then there is no logic to restricting abbreviations to only the latest, greatest, and newest of things; the book/web-version is needed to help decipher the not-so-new and not-so-great and oldest of abbreviations as well.

   The box at the bottom of the front cover is a contrived attention-getter to show how abbreviations are used. The abbreviations are real, just the story is contrived. I would be surprised if most readers could decipher more than half of the abbreviations used since many are not in common use. It reads as follows:

   …81 YO WDWNMAM POPTA. BIBA, admitted to CPETU c/o PND & DOE. TBNA in ED last wk for CP releived by NTG. Prev Adm for PTCA 1995, THR 2005, ICD 2007, IWMI 2010. ATSO Dr Hayley.

   Translated as intended, it reads:

   …81 year old well-developed, well-nourished, Mexican-American male passed out prior to arrival. Brought in by ambulance, admitted to chest pain evaluation and treatment unit, complained of paroxysmal nocturnal dyspnea and dyspnea on exertion. Treated but not admitted in Emergency Department last week for chest pain relieved by nitroglycerin. Previous admission for percutaneous transluminal coronary angioplasty 1995, total hip replacement 2005, implantable cardioverter defibrillator 2007, inferior wall myocardial infarct 2010. Admit to the service of Doctor Hayley.

   On the positive side, the use of abbreviations in this example-
   • Saves time for the writer
   • Saves space
   • Lessens the possibility of misspellings
   • Allows for fitting information into restricted space provided on a form or computer

   On the negative side, will this uncontrolled use of abbreviations result in
   • Incomplete or erroneous communication with non-emergency room personnel?
   • Puzzling documentation?
   • An increase in the time necessary to train health personnel?
   • Delays in initiating treatment?
   • Patient harm?

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

  1. Hendrickson, R ed. The Science and Practice of Pharmacy, 21st ed. Phila., PA; Lippincott Williams and Wilkins, 2006.

  2. CBE Style Manual, 5th ed. Bethesda, MD; Council of Biology Editors; 1983.

  3. Council of Science Editors, Style Manuel Committee, Science style and format: the CSE Manual for authors, editors, and publishers. 7th ed. Reston (VA):The Council; 2006.

  4. Cheng TO, Julian D. Acronyms of cardiologic trials - 2002. Int J Cardiol 2003;91:261-351.

  5. Facts and Comparisons, St.Louis.Wolters Kluwer Health (
   If you encounter abbreviations which are not in this book or on the web-version, please send them to --
   605 Louis Drive, Suite 508 B
   Warminster, PA 18974
   or E-mail to
   or fax them to 1-215 442 7432

   Have you investigated the web-version of this book?
  • It is instantaneously searchable for the meanings of abbreviations
  • It is reverse searchable (search for all abbreviations containing the word "cardiac")
  • Each week, about 50 new entries are added
  • When a word is clicked, you are transported to the Wikipedia definition/monograph