Looking up health information is the third most common online activity among US. Internet users, with eight out of 10 Internet users reporting doing so, according to a new report. Key Findings Among Internet users who go online for health information: 48 percent said they search for online health information on behalf of someone else; 36 percent said they use the Internet to look up health information for themselves; and 11 percent said they search for online health information for themselves and for others. According to the report, smart phones and mobile devices have changed how people use the Internet to search for health information. Researchers noted that pregnancy, herpes and sexually transmitted infections were among the most common health searches on Yahoo’s mobile site, but that the terms did not appear among the top health searches for non-mobile search engines.