An online medical reference library, CcsPublishing.com is the gateway for the Library of the National Medical Society Library, a resource aimed mainly for healthcare professionals and doctors where they’ll have access to a huge collection of textbooks and medical reference material, though they need to create an account and pay a yearly subscription fee.
This site also has a medical diagnosis tool which allows users to input information on symptoms, discomforts and other problems, and the system automatically figures out what could be wrong with the person, and provides treatment suggestions, though you also need to be a member of the library in order to access the results, which seems like a really sensible thing to do in order to stop self-medication. Even if doctors don’t use the system to get a diagnosis, the questionnaires available from the site will prove definitely very useful as they will draw attention of the physician to critical areas or spots they might have missed. The site is extremely simple to use, and all diseases, conditions and health problems are listed in alphabetical order, though it would seem sensible to have some form of thematic order as well. Maybe the tag cloud form could work for this system? 
