The Internet has made it possible to self-diagnose virtually any ailment right from a mobile device or computer without having to step foot into a doctor's office. Sites like WebMD are unparalleled in terms of convenience, offering a general diagnosis in minutes with the potential to save hundreds or even thousands of dollars in medical bills.

But just how accurate are online symptom checkers (and do you really want to gamble with your health)?

Researchers from Harvard Medical School recently completed the first large-scale study on the accuracy of online symptom checkers. Study leader Ateev Mehrotra said his team created a list of symptoms based on 45 specific medical scenarios. The symptoms were then entered into 23 commonly used symptom checkers in the US, the UK, the Netherlands and Poland.

Results showed that symptom checkers were only able to correctly identify an illness on the first attempt about a third of the time. A correct diagnosis was included in the top three suggestions 51 percent of the time. When looking at the top 20 suggestions, the rate of success rose to just 58 percent.

Or in other words, symptom checkers are free for a reason.

Mehrotra noted, however, that getting advice about whether or not to seek medical attention and how quickly one should visit a doctor can be more important than a correct diagnosis. Conversely, the team also found that online checkers were quick to recommend a doctor's visit when in reality, self-treating was sufficient for a particular ailment.