Nothing makes a doctor cringe faster than the patient who says, "I think I must have diagnosis X because that’s what it says on the Internet."

"Why do patients come to see me if they already 'know' what they have?" one doctor asked me. "Why do they think I bothered going to medical school if it’s so easy for them to diagnose themselves?"

He was right, of course. While the Internet can be a powerful learning tool for health and medical information, it can also be dangerous when its information is translated incorrectly.

The term "cyberchondriac" was coined to describe people who use the web to support their self-diagnosed fantasies of dread diseases and chronic symptoms. They get a twinge here, or a sniffle there, then they run to the Internet to look up their symptoms. The next thing you know, they have diagnosed themselves with Parkinson's or cancer or something worse.

But that’s the key to the problem -- self-diagnosis. When we begin to experience symptoms that seem strange to us, it’s human nature to want to know what’s causing them. Easy access to information makes it too simple to punch in a few keywords, then come away with a result. The Internet provides a first opinion. By the time we see the doctor, we're already seeking a second opinion.

My opinion? There are too many variables that make it almost impossible for you to diagnose yourself accurately without the input of a professional - a doctor or a nurse practitioner - people who diagnose for a living.

I'm not going to tell you not to look up your symptoms because that's like trying to stop a boulder from rolling downhill. But I do suggest that you learn about options from your doctor before you leap to conclusions.

Your doctor or nurse practitioner is trained to assess your history and symptoms, order tests to confirm or contradict, and use her experience and expertise to arrive at an accurate diagnosis. Those are skills you don’t have, no matter how astute you are with a search engine. Further, even if you were to diagnose yourself accurately, you can't treat yourself. You can't write prescriptions or perform surgery. You need to see your doctor anyway!

Yes, it’s possible your doctor will have trouble arriving at a diagnosis. It’s even possible your doctor will be wrong. If so, then you can use the Internet to review alternatives so you can partner with your doctor to arrive at a valid conclusion.

Once you have a doctor’s diagnosis, then by all means, use the Internet to learn everything you can about both the diagnosis and your treatment options. Be sure you use credible sources, of course. Your patience will pay off because you will have your doctor’s insights as a starting point.

A smart patient knows to let the doctor do her job, and to use the Internet to expand his knowledge.

Edited by Alison Stanton