WHO lists it among the top 10 killers in the world. While a British National Health System survey in 2009 reported that 15% of its patients were misdiagnosed. According to National Center for policy analysis US; An estimated 10 percent to 20 percent of cases are misdiagnosed, which exceeds drug errors and surgery on the wrong patient or body part, both of which receive considerably more attention. One report found that 28 percent of 583 diagnostic mistakes were life threatening or had resulted in death or permanent disability. Another study estimated that fatal diagnostic errors in U.S. intensive care units equal the number of breast cancer deaths each year -- 40,500. While diagnostic errors are the leading cause of malpractice litigation, the vast majority of errors do not result in legal action. Because many go unreported, it is difficult to gather detailed data on how prevalent misdiagnosis is. A recent study on the Veterans Administration hospital system in Texas estimated that there are at least 500,000 missed diagnostic opportunities that occur out of the 500 million primary care visits that occur annually in the United States.

I have heard and read about medical misdiagnosis , how serious is it?

"There is probably nothing more cognitively complicated than a diagnosis" - Graber, a senior fellow at RTI International.

According to doctors, misdiagnosis has occurred for quite some time. As far back as 1991, Harvard University found that misdiagnosis accounted for 14 percent of all adverse events and that 75 percent of these errors involved negligence. Many doctors who make a misdiagnosis are unaware that they have made a misdiagnosis because patients simply seek another opinion or do not find out until years later. The reality is that fixing diagnostic errors will be challenging given that arriving upon a medical diagnosis is a complicated and multifaceted procedure. A survey found that 96 percent of physicians felt that diagnostic errors are preventable while half said they encountered at least one per month.

Does my physician know that I am being misdiagnosed?

First and foremost remember diagnoisis is not a one time activity, it is a sustained activity trying to find clues that match a disease pattern. You are an important player and you, your physician, your family care providers, diagnostic labs together need to work at this. Your body knows more than you! you need to trust your instincts, and even if it means you are over reacting so be it.

Listen to your body and watch for clues that your diagnosis might not be quite right.
Different medical conditions often have similar symptoms. It can be very difficult to distinguish some conditions from others. If your symptoms are too generic you need to be more careful because diseases have signatures and are associated with multiple symptoms, too common a symptom makes it more difficult to match.
Communicate to find out, ask your physician "Could it be something else?” and “How did you arrive at this diagnosis?” if your doctor is busy for a face to face interaction mail him or message him, he will get back to you, every doctor cares for his/her patient and is always focussed on getting it right the first time.
If the prescribed medicine is not helping as expected to ease your symptoms and make you better, that is another indicator. Easiest thing is to maintain a patient diary where you track your symptoms.
Educate yourself, sign up to a patient community, you will get enormous amount of help from people who have had similar experiences and they will be glad to reach out.

How do I know if I am being misdiagnosed?

What are some common conditions that get misdiagnosed?