Acronyms and abbreviations are used extensively in medicine, science and technology for good reason—they are more essential in such fields. It would be difficult to imagine how one could write down chemical and mathematical formulas and equations without using abbreviations or symbols.

Abbreviations and acronyms used in medicine can be grouped into two broad categories. The first consists of official abbreviations and symbols used in chemistry, mathematics, and other sciences, and those designating weights and measures, whose exact form, capitalization, and punctuation have been determined by official governing bodies. In this category, they mean only one thing (e.g., kg is the symbol for kilogram and Hz for hertz), and their form, capitalization, and punctuation have been established by the International System of Units (Systeme International d'Unites). Abbreviations in the second group, on the other hand, may appear in a variety of forms, the same abbreviation having a different number of letters, sometimes capitalized, at other times not, with or without punctuation. Moreover, they may also have numerous meanings. The abbreviation AP may mean alkaline phosphatase, acid phosphatase, action potential, angina pectoris, and many other things.

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