• 59 percent of U.S. adults say they looked online for health information within the past year.
• Of those, 8 in 10 say they started their last health inquiry at a general search engine. Smaller groups started at a dedicated health website or social networking site.
• 70 percent of U.S. adults got information, care, or support from a doctor or other health care professional.
• 60 percent got information or support from friends and family.
• 26 percent got information or support from others who have the same health condition
Source: Pew Research Center Internet & American Life Project
The results reported in "Health Online 2013" come from a nationwide survey of 3,014 adults living in the United States. Telephone interviews were conducted by landline (1,808) and cellphone (1,206, including 624 without a landline phone). The survey was conducted by Princeton Survey Research Associates International. Interviews were done in English and Spanish by Princeton Data Source from Aug. 7 to Sept. 6, 2012. The margin of sampling error for the complete set of weighted data is plus or minus 2.4 percentage points.
Pat Stewart was wheezing like a whistle.
An upper respiratory infection had run on for several weeks, which the Chattanooga resident says is unusual for her. So she headed for the Internet.
"After checking out the possibilities on a couple of reputable medical sites, I felt it would be prudent to revisit the doctor," she says.
A follow-up in the doctor's office involved an X-ray and computed tomography (CT) scan. The diagnosis: Asthma.
"Sometimes peace of mind can be priceless," Stewart says. "Most recently I did it for a friend who thought they might have temporal arteritis. They saw their doctor and ruled it out through a couple of tests. I would never rely on the Internet, but there is information out there that could keep you from ignoring a serious problem."
Now on the mend, Stewart is among the millions of people diagnosing their own conditions online. One in three Americans look to the Internet when trying to fix what ails them or someone else, according to a study released by the Pew Internet Project.
About half of those who do online triage follow up with a visit to the clinic. In 40 percent of those cases, a medical professional confirmed the diagnosis.
"Online health information is available day or night, at no cost, and the Internet has become a de facto second opinion for many people," according to a statement by Susannah Fox, lead author of the Pew report. "But this study shows that the Internet is just one piece of the puzzle. Clinicians are still central."
While Fox and local experts caution that the Internet isn't the same as a visit to a medical professional -- and can offer scary or misleading answers -- it's a key resource for patients that health care providers are starting to embrace.
Chattanooga gynecologist Rink Murray says he's not against people self-educating themselves, but advises that people not believe everything they read.
"One of the great challenges is the amount of bad or incomplete information on the Internet," Murray says. "I have had some patients who are very well informed and work in a collaborative way with their physician. I've seen other patients who seem to think Internet information is everything they need and then proceed to work against their own interests because they don't understand the subtleties, exceptions or things that might modify their situation."
So do the research, he says, but be smart about it.
"My best advice is to read all you want, except chat rooms which are the riskiest for bad advice, but keep an open mind and work with your doctor. If you feel the doctor isn't working with you or can't or won't take the time to help you understand why he or she disagrees with your researched conclusions, get a second opinion," he says.
Fox, who has studied online health habits since 2000, describes the trend of doctors actually saying it's OK for patients to start with Internet research as a "sea change."
"In the beginning, medical professionals were often very resistant," Fox says.
But it's not for everyone. Knoxville resident Coni Haley, formerly of Fort Oglethorpe, Ga., says she never turns to the Internet for a self-diagnosis.
"I make it a point not to look at the Internet for medical information. Sometimes it will frighten people for no reason," she says.
Like Haley, Anne Butler of Chattanooga says her medical research on the Internet "always ends with me having cancer."
"The Internet is a good tool, but it never takes the place of seeing a qualified health professional," says Kevin Lusk, spokesman for the Chattanooga-Hamilton County Medical Society. "A lot of the times, the Internet can cause more panic than needs to be. Self-diagnosis can be dangerous."
According to Pew, 80 percent of the people who seek health information online start at a general search engine, such as Google or Bing. The Mayo Clinic's website for consumer health information, one of the most credible resources online, draws an average of 100 million page views a month.
But even there, doctors say, people shouldn't get too anxious about what they might find. They also should follow up with their doctor if they have questions.
"When you search 'headache' and (the Internet) comes up with brain tumor, it's not likely going to be the first thought on 'headache' that your doctor will have," says Dr. Roger Harms, editor-in-chief of Mayo's consumer information site.
McClatchy Tribune News Service contributed to this report.