Medical Abbreviations & Acronyms

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

For completeness, the index includes abbreviations that are not recommended for use. 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. See: List of Error-Prone Abbreviations and Symbols (PDF) by The Institute for Safe Medication Practices for an excellent reference.