There are privacy concerns about health networking sites, but you can minimize the risks by following some simple steps.

First, consider what you hope to gain from joining an interactive site. If you just want to learn about a condition, you can remain a "lurker" and read message boards without responding. If you want to connect with others, you may have to reveal some personal information to the company but can stay anonymous online.

'Sell my data'

If you have a serious disease, you may decide to give health details to a reliable research site. Some users hope their information can be used to help find treatments. "The patients say, 'Sell, sell, sell my data. I want the drug companies to have it,'" says Benjamin Heywood, co-founder and president of PatientsLikeMe. Members with conditions including nerve disorders, AIDS and depression offer their anonymous data to his site.

A reputable site clearly informs members about its aim to sell data to businesses researching treatments. Check a Web site's privacy policy, typically found at the bottom of the page though it can appear anywhere as "Privacy Policy" or "Disclosure." Most people never read these, but they reveal matters such as what information the site collects and how much control you have over their distribution and retention of you data.

The Wellness Community's privacy policy, for example, notes that users can opt for varying levels of privacy. "We do not collect personally identifiable information from you unless you provide it to us voluntarily and knowingly. ... If you choose to join an Online Support Group (OSG), we will collect information regarding your cancer diagnosis, the date of diagnosis, and ethnicity information. ... If you choose to participate in our public discussion board, please remember that any information that you disclose in this area becomes public information."

Privacy policies sometimes include refresher courses on cookies, those bits of information sent to your hard drive while you're viewing a site. "We may use both session Cookies (which expire once you close your web browser) and persistent Cookies (which stay on your computer until you delete them) to provide you with a more personal and interactive experience on the Site," DailyStrength tells users. "Persistent Cookies can be removed by following Internet browser help file directions. If you choose to disable Cookies, some areas of the Site may not work properly."

Trusera reminds members not to send private information by email or instant message, which are not recognized as secure. Instead, log onto the secure, firewall-protected site to send correspondence.

No guarantees

Many sites say that they're using the latest in security technology but acknowledge they can't guarantee that no one will be able to break in and get access to your personal information.

Members of online communities often choose to give more information than the Web site requires. Some members disclose their identity and details about their health in public forums. However, some sites caution users about the possibility of discrimination from insurance companies and employers.

Another risk: Some medical professionals' blogs have revealed information about patients. This has even included photos of patients in some cases, researchers at the University of Pennsylvania found. If your doctor or therapist writes a blog, check it out and insist that no identifying details of your case be published without your consent.

Note that the Health Insurance Portability and Accountability Act (HIPAA), federal regulations that protect the privacy and security of health information, applies only to healthcare providers--not online communities. You have to rely on their privacy policies and your own common sense.

More: Learn how to use the Internet safely.