If you or a family member has general health questions, where do you turn? Often after hearing a diagnosis, a patients will ask his doctor some basic questions. But when he gets home, he thinks of more questions and concerns. Short of leaving lengthy messages for your doctor, where can you turn for additional information?

In 2007, 160 million Americans - roughly half of the U.S. population - used the Internet to search for health information. But how do you, the health care consumer, know the information you find is legitimate? Here are six suggestions to help sift the quality from the quackery:

Where does the information come from? How easy is it to find contact information? Is the site easy to navigate?

Look at the "About Us" page. Is the site run by a branch of the government, nonprofit institution, professional organization, health system or hospital, commercial organization or an individual?

Examples of good sources of health information are the National Institutes of Health, U.S. Centers for Disease Control and Prevention, Johns Hopkins University, Mayo Clinic, American Heart Association and the American Cancer Society.

If contact information is hard to find, or you can't tell who runs the site, you might want to look elsewhere for legitimate health information. A site that recommends a particular drug by name should be explored to see if the drug manufacturer is a site sponsor and other sources consulted to see what they say about the drug. A Web site created by a person after their own heart attack might be created with the best of intentions, but compared to information from the American Heart Association site, that independent site is not medically authoritative.

What is the purpose of the site?

Is the site a chat or discussion room? Are they trying to sell you a product or service? Trying to raise money or just trying to inform?

Taking medical advice from a chat room because "Suzi from Sheboygan" says "her husband has the same heart condition you do and it worked for him" also falls into the unadvisable category. Your physician has your medical history and evaluates your health as a whole when he or she makes recommendations. Lab tests, blood pressure, weight and lifestyle are just a few of the details that are factored into your physician's guidance. Any site that offers a diagnosis just based on your description of your symptoms should be explored with caution.

If it sounds too good to be true, it probably is.

For only two payments of $14.95, only available for the next 15 minutes, a bottle of pills with a secret ingredient from the Tambopata Rainforest can be shipped to your home. Made from a special chemical secreted by the Hyla rhodopepla tree frog, the "supplement" will make you lose weight, regrow hair, build muscle, shrink hemorrhoids, cures all known skin diseases, eliminates bad breath, flatulence, constipation, diarrhea and wrinkles, and attract the opposite sex.

Does the Web site promise a miracle cure? Is it selling you a product? Does it claim to have the only remedy for your illness? While this example is extreme, people are tricked daily into spending money on miracle cures from goat's blood serum to unlicensed stem cell treatments.

Look for evidence.

Does the information sound too scientific? Does it reference actual published research?

If a site giving you medical advice uses big words, confusing scientific sounding lingo and doesn't detail where and when the research was conducted and published, we suggest leaving the site and finding a different source for medical information.

A good consumer health site will explain clearly and completely, "big words" or medical terms will be hyperlinked or defined and the location of where the information came from will be posted or better yet, hyperlinked.

Shop around to see if other Web sites support the information you have found. You would ask for a second opinion from a doctor, so why would you automatically believe what is posted on the Internet?

How old is the information? Who evaluated it before it was put on the Web site?

Would you rely on a map of Missoula from 1970 to help you get across town? While the main streets are the same, the amount of growth and change on side streets would be hard to overcome.

Medical information can change quickly, and a Web site that is years out of date may provide incorrect or dangerous information.

Protect your privacy.

Avoid Web sites that ask for personal information such as name, address, date of birth, gender, mother's maiden name or credit card number before providing you information.

Look at the site's privacy policy to see if your information is really being protected. If the privacy policy states that they will "share your information with companies that provide useful products and services" they will be giving or selling your name and address to companies that will probably try to sell you something. Do you really need more junk mail?

So where can you go online to find easy to understand consumer health information? While there are many good Web sites that fit these criteria, most are flooded with advertisements. We recommend MedlinePlus.gov - the National Library of Medicine and National Institutes of Health work together to create this site. It combines the best of everything, easy to use, up-to-date and accurate information and, best of all, no advertisements. The site offers interactive tutorials, surgery videos, links to health topics and drug information and with "Go Local" links to local health care resources. Latest news and research information is linked within the health topics and even age-based disease information is linked for children, teens and seniors. MedlinePlus is easy to navigate. Check it out and share it with your friends.

Dana Kopp is medical librarian and director of the Center for Health Information at St. Patrick Hospital and Health Sciences Center.