The following sites provide access to health-related reference works, as well as reliable sources of health information on the Web.

CDC: Centers for Disease Control and Prevention
http://www.cdc.gov
Contains a wealth of reliable health information, including health and safety topics, health statistics, travelers' health information, and more.

Complete Guide to Understanding Cancer
http://www.mesotheliomagroup.com/understanding-cancer/
Publication of the Mesiothelioma Support Group.

TheFreeDictionary.com
http://www.thefreedictionary.com/
A broad-based online resource with about 2,000,000 articles and definitions from leading dictionaries and encyclopedias. Resources include Stedman's Medical Dictionary, as well as legal, computing, and financial dictionaries, acronyms, and two general encyclopedias.

Healthfinder
http://www.healthfinder.gov/
Gateway site to reliable consumer health information, from the U.S. Department of Health and Human Services.

LocatorPlus
http://locatorplus.gov
The National Library of Medicine's Online Catalog of books, journals and audiovisuals.

Martindale's Reference Desk
http://www.martindalecenter.com/
Incredible collection of online reference tools on everything from Aerospace medicine to Zoology: calculators, dictionaries, shareware, and more.

MedBioWorld
http://www.medbioworld.com/
One of the the largest medical reference sites. Links include 6,000 medical journals in 80 subspecialties, and the home pages of 4,000 medical associations. Other research tools include medical glossaries, disease databases, clinical trials and guidelines, and medical journals offering full-text articles.

MedicineNet.com
http://www.medicinenet.com/
Provides easy-to-read, in-depth, authoritative medical information for consumers. Lengthy articles cover diseases, symptoms and signs, tests, and drugs. The MedTerms dictionary contains over 16,000 terms, including abbreviations, acronyms, jargon, eponyms, and medical history not easily found in other online medical dictionaries.

MedlinePlus
http://medlineplus.gov
The National Library of Medicine’s consumer health information website.  Contains links to MEDLINE, as well as dictionaries and other reference tools, physician and hospital directories, and specialized health science databases.

Medical Subject Headings (MeSH) Browser
http://www.nlm.nih.gov/mesh/
An indispensable thesaurus for medical indexers; used for indexing MEDLINE and other NLM databases. Also searchable via PubMed.

Merck Manuals Online
http://www.merck.com/pubs/
Contains searchable full-text online editions of resources such as Merck Manual of Diagnosis and Therapy, Merck Manual Home Health Handbook, and Merck Veterinary Manual.

PubMed
http://www.ncbi.nlm.nih.gov/PubMed/
PubMed, a service of the National Library of Medicine, includes over 14 million citations for biomedical articles back to the 1950s. These citations are from MEDLINE and additional life science journals. Includes links to many sites providing full text articles and other related resources.

RxList
http://www.rxlist.com/
Searchable database of prescription drugs, containing physical descriptions, indications, adverse effects, etc. Includes a list of the 200 most-prescribed products.

The Ultimate Guide to Self-Employed Health insurance
http://www.healthinsure.org/the-ultimate-guide-to-self-employed-health-insurance/
An in-depth guide to health insurance selection issues and terminology, from HealthInsure.org.

WebMD
http://www.webmd.com/
Services that help physicians, consumers, providers and health plans navigate the complexity of the healthcare system, including dictionaries, symptom checkers, and information about physicians and insurance plans.

YourDictionary.com Specialty Dictionaries
http://www.yourdictionary.com/specialty.html
Full-text English language dictionaries for biology, chemistry, dentistry, medicine, psychology, sociology, and other disciplines.