Chances are you've done it --searched the Internet to figure out what that unexplained ache or pain is.

About 80 percent of Americans say they've gotten medical information online, according to a recent survey.

What you're likely to find is the worst possible diagnosis. Which breeds a whole new type of fear--cyberchondria.

Click play for more on the pros and cons of using the Web to get medical advice.

"I sort of think of the Internet as the cutting edge of hypochondria," said Dr. Kelli Harding of Columbia University. "There's so much information and just because you have a headache doesn't mean it's a brain tumor."

So how much surfing is too much?

It's true. People who research a medical condition often needlessly worry about the worst case scenario, but the opposite is also true. Sometimes doctors are proven wrong by their Internet savvy patients.

Stacey Vaselaney may have saved her own life.

The 40-year-old complained to her doctor about throat pain after drinking alcohol and noticing a bulge in her neck.

"[My doctor] really was pretty quick to dismiss that," she remembered. "He really was leaning towards a bacterial infection, or some sort of infection."

But Vaselaney researched her symptoms on the Internet and up popped sites about cancer. She made an appointment with a cancer specialist who said her self-diagnosis was right.

"When I heard Stacey's story, I presumed it was going to turn out to be Hodgkin's Disease because alcohol-induced pain in lymph nodes is a rare presentation, but it happens," Dr. Alan Lichtin said.

Because Vaselaney caught her cancer early, her future looks good.

Although mistakes are made on both sides, well informed doctors and patients combined, equal the best medicine.

*Originally aired January 5, 2008