Developed by the World Health Organization, the ICD is the classification used to code and classify mortality data from death certificates. It was designed to promote international comparability in the collection of mortality statistics. The site contains access to the 9th revision that includes all updates through October 2002 and the August 2005 10th revision. These versions are maintained by the U.S. National Center for Health Statistics. http://www.cdc.gov/nchs/icd9.htm

MHI is a subject index to illnesses and diseases. It includes a medical glossary and is aimed at all who are in need of finding qualified medical information. http://www.medhelp.org/

OrphaNet is the portal for rare diseases and orphan drugs.  For rare diseases, it also provides synonyms, ICD, summary, detailed text, outpatient clinic, support group, clinical laboratory, research program, and links to other websites.  The site a keyword search index and alphabetical list of diseases. http://www.orpha.net/consor/cgi-bin/index.php

The site contains an extensive alphabetical list of rare diseases. For each entry there is a definition, hypertext links to the definitions keywords, synonyms and see related' links. This site also is accessible French, Spanish, German and Portuguese and is maintained by Health on the Net, a Swiss based ngo. http://www.hon.ch/HONselect/RareDiseases/index.html