Medical Abbreviations & Acronyms

OpenMD’s index includes 4,500 common medical abbreviations. Meanings vary by institution and clinical context. When available, the context and original Latin term are provided in parentheses after the English definition.

While this index was compiled from credible sources, it has not been medically reviewed. When in doubt, always check with the organization or individual who authored the abbreviation in question to verify the author’s intended meaning.

About Medical Abbreviations

The use of certain abbreviations can be dangerous and lead to patient injury or death. Examples of dangerous abbreviations include:

  • IU (international unit): may be confused with “IV” (intravenous)
  • µg (microgram): may be confused with mg (milligram)
  • U (unit): may be mistaken for “0” (zero), increasing a dosage tenfold

To minimize confusion, many organizations publish “Do Not Use” lists of easily-confused abbreviations and symbols. For an excellent reference, see the List of Error-Prone Abbreviations and Symbols (PDF) published by The Institute for Safe Medication Practices.