Significantly, one out of five respondents said they had clicked on an online ad for a prescription drug or over-the-counter remedy. The ad network BURST! found that women are far more likely than men to conduct health research online. On average, 73.9 percent of women will research health topics online, compared to just 62.1 percent of men. Eighty percent of women ages 25 to 44 said they researched health issues online--more than any other segment. At just 38.2 percent, males 18 years and younger are least likely to seek health info online.

Some representatives from health content sites within BURST!'s network said the survey results were consistent with their understanding of the market. "The findings do not surprise me," said Denise Wood, a representative for health site Health Discovery, noting that the majority of the Web site's 30,000 members are women who seek support with health and diet issues.

Dr. Vincent Iannelli, president of the health site Keep Kids Healthy, added that consumers generally benefit from extra knowledge. "Doctors may not like it when patients come to a visit with several sheets of paper that they printed from their favorite Web site, but a better-informed patient can be a healthier patient," said Dr. Iannelli. He qualified this statement with the warning that patients should not attempt to take serious medical situations into their own hands.

Among respondents who said they use the Internet as a health resource, 47 percent have visited a condition-specific Web site, chat room, or forum to gather information. Additionally, 36 percent sought out commercial health care sites, 26.1 visited their health care providers' sites, 26 percent went to government sites, and 21.1 percent went to the Web sites of pharmaceutical companies.

BURST! found that the use of pharmaceutical companies' Web sites increases with age: thirty-two percent of those 65 years and older visit such sites, compared to 16.4 percent of respondents 24 years and younger.

Half of those surveyed said they had used the Web to gather information about symptoms of specific illnesses, while 43.9 percent sought treatments for a specific illness online. In addition, 30.9 percent researched specific drug remedies; 28.6 percent were after nutrition-related material; 26.2 were interested in vitamins and supplements; 25.1 percent sought diet or weight loss programs; and 22.5 percent sought prescription/over-the-counter remedies, while 20.7 percent deferred to the Web for information on health and beauty aids.