We’ve all done it — searched medical conditions and symptoms online, hoping to self-diagnose what those mysterious red bumps are, and wishing against all odds that our search offers good news (“Please, please tell me these aren’t bedbug bites”).

Sometimes, the frequency of Internet searches for health information can signal a brewing epidemic. That’s how Google Flu Trends works, for instance — tracking flu-related searches to determine global flu activity.

But more often, what people search for online is simply a reflection of the latest news or gossip, even on medical websites. on Monday, WebMD, which logs more than 83 million visitors per month, released data on the top stories and searches that most held its readers’ interest over the past year. not surprisingly, the site’s most popular story in 2010 was a slideshow about bedbugs, and its top trending search was “bedbugs” (in 2009, the top trending search was “head lice,” suggesting that people really like reading about creepy infestations). (More on TIME.com: How to Build Your Own Bedbug Detector)

WebMD’s second most popular trending search was “throat cancer,” another ripped-from-the-headlines area of interest: in August, actor Michael Douglas announced he was battling throat cancer, and images of his frail frame were splashed on the covers of tabloids. Douglas’ cancer was also the top celebrity-related health topic and the third biggest news story this year on WebMD. last year, it was another celebrity’s health condition that came in second place in the top trending-searches list: “anal cancer.” In June 2009, actress Farrah Fawcett died after a long fight with the cancer.

Rounding out this year’s top five trending searches: in third place, whooping cough (No. 3 was swine flu in 2009); gluten (2009′s acai berry); and vitamin D (taking over from resveratrol last year).

What other health topics were popular with WebMD readers this year? the answer varies depending on whether you are a man or a woman. most popular topics for women were menstrual problems, fatigue, super foods, thyroid problems, and sex and relationships. not surprisingly, “sex life” landed the top spot in popular topics for men, followed by “questions about penis,” testosterone, flat abs and STDs. If you weren’t convinced of men’s obsession with sex before, this leaves little doubt. (More on TIME.com: Study: Does the Pill lower Sex Drive?)

In the end, WebMD’s data may not say much about the physical health of the nation, but at least it confirms that you’re not the only one wondering about the 5 things You Didn’t know about Your Penis.

Click here for the full round-up on the top health searches, top health question and top shared stories of the year.

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Earlier this baseball season, San Diego Padres pitcher Tim Stauffer diagnosed himself with appendicitis after consulting a medical site on his iPhone. he informed his trainer and soon after, his appendix was successfully removed.

Stauffer is among the 8 in 10 Internet users hitting the Web to get their health-related questions answered, according to the Pew Internet and American Life Project. although medical websites such as Web MD and Mayo Clinic provide key insights into identifying and treating various ailments, experts warn they also make it easy for people to misdiagnosis health problems and can lead to “cyberchondria,” or anxiety borne from online health-related searches.

“It’s important to stay up on health-related information … but because information on the Web is so unfathomably plentiful, so readily available, and so unsorted, it’s easy for someone to jump to the conclusion that they have a brain tumor when in fact it’s just a sinus infection,” according to Judy Segal, professor of English at the University of British Columbia who works on the cultural studies of medicine.

To complicate matters further, a lot of the medical information available for free online is actually accurate and reliable, experts say.

“The problem is, though, that even when the information is reliable, our ability to know what to do with it isn’t,” Segal told MyHealthNewsDaily. “Medical problems are often complicated, and someone without a medical background may jump to false conclusions.”

Segal believes the Internet encourages hypochondria, itself a medical condition. Hypochondriacs are people so concerned about particular diseases that they tend to not trust physicians when they are told there is nothing wrong with them. [Read: Top 10 Controversial Psychiatric Disorders ]

“When there’s so much information out there, it’s easy to focus on what could be possible, even if the chances are very slim,” Segal said. “The Internet brings out the hypochondriac in all of us.”

A 2008 Microsoft report called “Cyberchondria: Studies of the Escalation of Medical Concerns in Web Search” also supports this theory. (Msnbc.com is jointly owned by NBC Universal and Microsoft.)

The Web has potential to fuel anxieties in people who have little or no medical training, and the large volumes of medical information, some of which is erroneous, may mislead users with health concerns,” the report states. “This can lead users to believe that common symptoms are likely the result of serious illnesses.”

Although most people go online to be reassured and learn something that makes them feel better, they don’t always leave with the sense of relief, said Arthur Barksy, a professor of psychiatry at Harvard Medical School.

“In most cases, people became far more worried after they turn the computer off than they were in the first place,” Barsky said. “People are exposed to the myriad of rare and awful diseases out there that they had never heard of that share their symptoms.”

Another variable fueling the growth of cyberchondria is pharmaceutical advertisements.

“Pharmaceutical companies are not only branding products, they are also branding conditions,” she said. “Magazine ads and television commercials tell consumers that their indigestion or their constipation – or even their poor mood – could actually be something quite ominous. someone watching at home could start to wonder if they have a more serious condition.”

American adults still rely on traditional sources of health information, even as many deepen their engagement with the online world, according to recent research from the Pew Internet and American Life Project.

Many Web surfers seeking out information on medical sites are looking for insights from people who are battling the same issues, said Susannah Fox, the Associate Director of the Pew Internet American Life Project.

“Doctors can’t provide the same level of detail as a fellow patient can about what it feels like to go through a certain treatment or to live with a condition,” said Fox, who is also the principle author of a March 2010 report on how the Internet affects how Americans interact with their health professionals.

Six in ten Web users living with a chronic disease access peer-generated health information, such as blog posts, doctor/hospital ratings, podcasts or customized health news updates to learn about medical treatments and procedures.

The access to medical information on the Web, however, has changed the doctor-patient relationship, the University of British Columbia’s Segal noted. Many patients arrive at a visit with print outs of information about new pills on the market or a condition they think they may have developed.

“It’s great that patients are becoming more informed,” she said. “However, it becomes a concern when people come in and think they know more about a condition than the doctor. you can learn a lot from being a patient, but doctors have years of medical training, experience and context that someone looking for information on the Internet does not.”

The Internet’s effects on medicine are not all negative. In many cases, it is bringing people closer to doctors in new, innovative ways. for example, ZocDoc.com — which launched in 2007 — allows people in Chicago, San Francisco, New York and Washington D.C. to book a doctor’s appointment online as though it was a dinner reservation. this concept gives people the opportunity to find a doctor quickly and on demand.

ZocDoc users can search for a certain type of a physician — from a pediatrician to a radiologist, psychologist or eye doctor, among others — and then narrow their search by selecting those that accept their insurance provider. Images of the doctors then appear on the screen, along with timeslots in which they are available to see a patient.

The doctor is in — online Some doctor are experimenting with online alternatives to doctor visits. Jay Parkinson — a doctor in Brooklyn, N.Y., who is often referred to as “The Doctor of the Future” — has also been a game-changer in the medical field by being accessible to patients beyond the confines of an office. In fact, he has no office — he runs most of his practice online.

After completing a residency in pediatrics and one in preventive medicine at Johns Hopkins, Parkinson began making house calls to patients in Williamsburg, Brooklyn, to avoid a large business overhead. he allowed patients to have access to his Google calendar so they could see his availability. he also offered them the flexibility to make payments through PayPal and even emailed, instant messaged and video chatted with them to follow up on a visit. News of his creative Web 2.0 methods created much buzz and his business grew.

“I look at email and instant messenger as augmenting real in-person relationships, especially when it comes to something as important as a doctor-patient relationship,” Parkinson told MyHealthNewsDaily.

“It’s pretty obvious this is how more and more people are communicating nowadays. If being a good doctor is also about being a good communicator, we should meet patients where they are. my young patients were online and wanted to communicate ‘normally,’ so embracing this route was a natural step.”