Nearly 100 million Americans go online for health information. Much of what they find is hard to understand, and often incorrect and incomplete. Consult several Web sites, but also check with a physician. In general, government and university sites are the most reliable.

National Institutes of Health
Not the prettiest of the lot, but for authoritative and reliable patient information without the hype, this government-sponsored network of sites is tops. Search NIH's 27 branches (the National Cancer Institute, for example) for detailed information and government research. Or click on Health Information and link to Medlineplus where you can easily navigate 450 topics, from back pain to amyotrophic lateral sclerosis (Lou Gehrig's disease). Also, a clinical trials database.

Food & Drug Administration
Good drug information. You can look up FDA-labeling for new drugs aproved since 1998 and find an exhaustive rundown on efficacy and safety. In the MedWatch section, look up drug-safety labeling changes since 1996 and alerts on drugs, dietary supplements and other products.

InteliHealth
Aetna U.S. Healthcare's portal gets content mainly from Harvard Medical School, though not all of the staff is academic. A recent article asks "Do cell phones cause cancer? (Answer: no.) Distinctive features include a section on dental health, a link to FDA drug safety alerts and interactive Cool Tools section.

Medscape
The latest news and information in 30 health categories, written by and for health care professionals. On a given day there might be 40 bulletins. Customize the home page to get news by specialty and sign up for weekly updates via e-mail. When the jargon gets too thick-and it will-you can always click over to the civilian site, CBS Health Watch, but it's less trustworthy.

OncoLink
Addresses both the clinical and human sides of cancer. Run by the University of Pennsylvania Cancer Center, this authoritative site covers the gamut from financial issues and symptom management to art and writing programs that help patients heal. Breast cancer information even covers pregnant woment and those with silicon implants.

Quackwatch
Debunks health care hype on the Web. Run by retired psychiatrist Dr. Stephen Barrett, this no-frills site blasts the claims of chiropractors, acupuncturists and homeopathic healers. Hundreds of articles attack dubious treatments for serious conditions, such as pultiple sclerosis. Links to government consumer sites.

YourSurgery.com
Before you go under the knife, check out this site run by Dr. Harold Portnoy, a Michigan neurosurgeon. Thoroughly details 50 surgical procedures, from heart valve surgery to Lasik vision correction. Clearly written and beautifully illustrated with diagrams and animated pictures, each section describes the anatomy of the body part in question, pathologies, symptoms and complications. Fast despite all the graphics.