If you’re convinced your headache is a brain tumor or those stomachaches mean you’ve got cancer, chances are you’ve been spending too much time surfing medical sites. “Though the Web has an abundance of medical information, it has the potential to increase anxieties,” explains Eric Horvitz, PhD, MD, principal researcher at Microsoft Research, who recently coauthored a study looking at healthfocused searches.

The research showed that when survey participants looked up basic symptoms and medical conditions, 90 percent of searches yielded results mentioning rare but serious diseases at least once. Unfortunately, this can lead to cyberchondria: the unfounded escalation of concerns about common symptoms based on search results.

For safer, less stressful searching, try these tips: Go to established health sites such as webmd.com and mayoclinic.org rather than searching the entire Internet.

Beware of websites that sound too sales-oriented or heavily promote a single physician, treatment or product.