It's Saturday night. You suddenly feel a stabbing pain in your big toe. You wonder, "Could it be serious?" So you do what 80 percent of American Internet users do--you run to the computer and type "big toe pain" into a search engine. You get 346,000 results. One site warns you to stop eating red

In the tangled web of fact and fallacy that is the Internet, how can you know if the health and medical information you dig up is reliable?

"If Web sites are offering consumers quick fixes or simple solutions to their medical problems, this should raise a red flag, as they are probably not the source of information you want to be using for your health care," says Harlan R. Weinberg, MD, author of a new book on the topic of online health information and director of the intensive care unit at Northern Westchester Hospital in Mount Kisco, N.Y.

Your computer is not your physician, Weinberg reminds.

"Patients should always remember that they need to have a doctor-patient relationship to review any information that they obtain off the Web as it involves their health care," he says.

Much of the health information on the Internet is accurate, timely and helpful, but it can also be confusing, outdated, inaccurate and downright frightening. So what should you look for when trying to sift online health facts from the fiction?

To help you make an informed decision, Weinberg suggests that you ask yourself a few questions: Who is the author of the information? Does a medical editorial board oversee the Web site? People with bona fide medical credentials should be reviewing the material before it's posted online.

Cyberdoc university

Ever wondered who regulates the information on the Internet? Here's the answer: No one. Anyone can post information on the Web, and what you just "learned" about your toe might have been posted by a fifth-grader.

For finding accurate, reliable and timely health information on the Web, your safest bet is to stick with sites sponsored by government agencies, universities or medical schools, hospitals and health systems, nonprofit health associations and foundations, and medical and science journals.

According to the National Institutes of Health, any health-related Web site worth its salt should have several characteristics: The Web site should clearly indicate who is responsible for the site and the information posted on it. In addition to identifying who wrote the material, the site should describe the evidence or research on which the information is based. Medical facts and figures should have references, for example, to articles in medical journals.

Also, someone's opinion or advice about that big toe of yours should be clearly set apart from information based on scholarly research.

A stitch in time

If the toe diagnosis you've accepted was posted the year the Internet was invented, you're definitely looking at outdated material. Web site sponsors should clearly indicate when articles were last reviewed or updated, usually with a line at the very bottom of the page. If there's no date, look for a copyright line.

Remember: Health information changes by the minute and you want to find the most recent data. The site should offer the most up-to-date research available.

Chatting it up

You've stumbled into a chat room where everyone is complaining about the same problem with their big toes. Hearing from fellow sufferers can make you feel better, but look for discussion boards where medical experts are online to answer consumer questions. While information you get from these sources can be helpful, it should not be the basis for decisions about your care. Again, don't let the information you receive online, even if it's from a "doctor," replace your own physician's medical advice. Use the information you gather online as a starting point for discussing your case and treatment options with your doctor, and never go to the Internet for a second opinion.

Weinberg's best tip: "Use the Web as a tool, and not as your sole resource for medical information or advice."

E-buyer beware

So, you've stumbled on a Web site that is offering to sell you an elixir to heal your medical woes. Don't plug in your credit card number just yet. Weinberg stresses that patients need to proceed with caution when making purchases over the Internet, especially when it involves medications.

"It raises very important questions about medication purity, as well as drug interactions, especially when you are buying from a source you may not be familiar with," he says.

According to the U.S. Food and Drug Administration, some companies use e-mail to advertise products or attract people to their Web sites. Make sure the accuracy of the health information hasn't been influenced by the company's desire to sell a product or service. If a Web site is pushing a miracle cure that sounds too good to be true, it probably is, so save your bucks.