Patients find plenty of health information on line, but not all of it is reliable Monday, February 21, 2011; 11:29 AM The Internet has no equal as an information storehouse. The trick is to know how to get right to a source of useful information and not waste time on Web sites that are biased, trying to sell you something or just plain wrong. Marvin M. Lipman, Consumers Union's chief medical adviser, recalls having a patient who made a Google search and somehow settled on an abdominal aortic aneurysm (a worrisome bulge in the body's main blood vessel) as the logical explanation for his midback pain. No reassuring on Lipman's part eased the patient's apprehension. It took a sonogram to convince him he wasn't at death's door. Lipman had another patient who was referred to him after her primary-care physician told her she had Graves' disease (an overactive thyroid). She arrived for her appointment armed with computer printouts of useful, accurate information and fully prepared to discuss the pros and cons of treatment options for her problem. Lipman says that nothing has changed the doctor-patient relationship as radically during his career as the Internet. As recently as 1995, about one in 10 American adults had online access; today, about three of four adults and just shy of 100 percent of teenagers use the Internet to get information and communicate with others, according to the Pew Research Center. The one-way flow of health information from doctor to patient is now a dialogue, or even, at times, a debate. Caveatemptor.com Google and Yahoo are among the most-used search engines. But almost anyone can pay these Web sites to display advertisements, or "sponsored links." And anyone with something to sell can set up a Web site with few if any checks and balances on what it says. While information sites such as AOL sometimes post paid links, many links are nothing more than ads for individual products. By searching Google for "flu symptoms," for example, ads may pop up for Kleenex, Tylenol and the homeopathic preparation called Oscillococcinum. The top "natural" (i.e., unpaid) search results might also include some sites marketing a specific product. For instance, a recent Google search on "enlarged prostate" yielded information from the Mayo Clinic and the National Institutes of Health but also the Web site for an unproven herbal product. The other dots You can also find health information on the generally commercial-free government Web sites (with addresses that end in ."gov") and academic ones (."edu"). Some not-for-profit organizations run Web sites (."org") that are ad-free, including ConsumerReportsHealth.org, which charges for some of its information, and some take advertising. Others are littered with advertising, and some are fronts for industries or manufacturers with a commercial agenda. Consumers visiting an unfamiliar site should always check the "About Us" section for clues about who is funding the content. Figuring out the pecking order among Web sites requires narrowing the choices to those that provide up-to-date, reliable and understandable information. Many qualify. No doubt your doctors can recommend personal favorites. This is Lipman's current Top 5 list: www.cancer.gov for information about cancer. www.cdc.gov for information about infectious diseases, travel medicine and epidemiology. www.fda.gov for information about drugs. www.medlineplus.gov for information about diseases. www.usp.org for information about medicine and nutritional supplements.