It's my opinion, and I might not be alone in it, that most doctors are quacks. I'm going to give you a good example of quackery:

A few years ago, my wife was experiencing lower back pain in the kidney area. The pain gradually became so intense that she could barely walk. So… she went to the doctor while I was at work (she took a day off). I don't know how the doctor diagnosed it as some kind of muscle strain or what kinds of tests he took. My wife said he didn't do anything. He did, however, prescribe muscle relaxers and put her on "bedrest" for two weeks. After a week, I noticed there was absolutely no improvement in her condition.

So, I started reading. I read on the Internet, I read health care books, and I read a huge medical manual, all trying to determine what was causing her problem. Then, after a few days, I happened across a book on nutrition. In it, I found out that lower back pain is sometimes caused by one or both kidneys being partially blocked. It recommended flushing with a drink high in citric acid, cranberry juice.

I went to the store, bought a gallon of cranberry juice, returned home, and had my wife drink it continuously until she couldn't drink any more. A few minutes later, she headed to the bathroom to do her thing. When she came out, she was walking perfectly straight and smiling. The pain was completely gone.

My wife did not get paid during the time she didn't work. So, we got hit with the double whammy: She had to pay to see a doctor (indirectly through her insurance) and lose pay that she would've made had she continued to work. All because of a doctor who didn't have the sense to consider that he was wrong in his diagnosis.

A friend of mine, at the time, told me that doctors are taught medicine and not nutrition and that's why they don't look for alternative means to solve the problem. I don't know if that's true or not, but I still think the doctor was a quack.