Official website of MedDRA, Medical Dictionary for Regulatory Activities. It is used by the pharmaceutical industry, regulatory authorities, and others for data entry, classification, and presentation of adverse event information.

The dictionary is available under paid subscription, but you can find documents with names of the classes and core terminology on the official website. To download open-access resources with the classes & terms, go to your language page from the home page. Scroll your language page down to the list of documents and open the first two (called "Introductory Guides" in English).