The University of Navarra’s Faculty of Medicine offers a monolingual dictionary in Spanish of medical terms. In this online dictionary, you can search for the terms in alphabetical order and many of the definitions include links to pages where you can learn more about the term.
Follow this link to find the dictionary: https://www.cun.es/diccionario-medico
The free and open access Royal National Academy of Medicine offers an online monolingual dictionary. Just like the website, this dictionary was designed to adapt to the content and to filter the searched term quickly and accurately. The search tool allows you to select different criteria so each user can obtain the most accurate results.
Follow this link to find the dictionary: https://dtme.ranm.es/index.aspx