A complete health reference and symptom checker that includes a virtual doctor that conducts an interview, analyzes symptoms, provides recommendations, and creates a personal health record.

The National Library of Medicine (NLM), on the campus of NIH in Bethesda, Maryland, is the world's largest medical library. It collects materials in all major areas of the health sciences and to a lesser degree in such areas as chemistry, physics, botany and zoology. The collections stand at 5 million items--books, journals, technical reports, manuscripts, microfilms, photographs and images. Housed within the Library is one of the world's finest medical history collections of old (pre-1914) and rare medical texts, manuscripts, and incunabula.

The leading source for trustworthy and timely health and medical news and information. Providing credible health information, supportive community, and educational services by blending award-winning expertise in content, community services, expert commentary, and medical review.

Find the Web's best health guides, medical reports, health news, and videos for any health topic.

CIGNA is a global health service company, dedicated to helping people improve their health, well-being and security. We provide an integrated suite of health, life, accident, disability and other wellness benefits to groups and individuals, serving over 45 million people throughout the United States and around the world

Extensive knowledge base of medical information on symptoms, diagnosis, and misdiagnosis of more than 20,000 medical conditions. Research causes of your symptoms or research treatments for diseases.