Transcript for Confessions of a Doctor
Going to the doctor. Think about it. You could be in surgery, laid out cold on a table and they're over you doing what? Well, you're about to find out everything about how some of them rake in the extra dough, to why you really have to wait so long in the emergency room. People seek me out to tell me their nightmare stories of medical mistakes. Reporter: Dr. Marty makary has a confession. If you were one of his patients back when he was a sleep-deprived icu intern, you were not in good hands. I mean, I was mismanaging patients, I'm sure. I changed the settings on a ventilator to make it even more difficult for someone to breathe. Reporter: The really scary part? Makary is one of the good doctors -- a leading surgeon at johns hopkins hospital in baltimore. Tonight, he's breaking the code of silence that keeps so much of every hospital's dirty laundry hidden from its patients. We can't be honest about the mistakes that are happening, which is why many people are surprised that medical mistakes are the number five cause of death in the united states. Reporter: It's equivalent to the number, like, of people who'd be killed in four jumbo jets crashing every week? It is a massive problem. Reporter: As makary recounts in his new book "unaccountable," error-prone doctors can blunder on for decades, receiving no condemnation other than a derisive nickname from their peers, dr. Hodad. I realized every hospital has a doctor that is locally referred to hodad. Reporter: That stands for? Hands of death and destruction. Reporter: That sounds scary? There's the florida surgeon who mistakenly amputated the wrong leg. The doctors at this rhode island hospital who operated on the wrong side of a patient's head three times. Even funmyny man dana carvey has spoken about a botched heart surgery by a doctor he claims could have killed him. So then they did another angiogram and they noticed the bi-passed the wrong artery. Reporter: Your reaction was? Come again, excuse me! You know, I couldn't believe it. Reporter: Even more astounding is a new study published in the journal of the american medical association, suggests that hospitals nearly triple their profits when they make surgical mistakes, because insurance plans will pay more for longer stays and extra care. As a nurse, we do see mistakes that doctors make all the time. And I think, that's an uncomfortable idea for the public. Reporter: Theresa brown has seen it all as a nurse. Doctors botching prescriptions, ordering procedures for the wrong patients, even disregarding the basics of hospital hygiene. There are doctors who don't wash their hands and that's a real risk to the patient. Reporter: But the medical field is so insular and self-protective, says makary, that even doctors with serious substance abuse problems can skate by. Try that again. Health care is a funny field. You can have a dui and walk right into the operating room the next morning. The faa would never allow that, because there are national guidelines for pilots. Arguing that it's part of public safety. Reporter: It's not public safety to have a surgeon operating on you who was wasted the night before? These are problems that happen when you have people who are in over their head and the oversight is very poor. Reporter: Take the case not long ago of dr. Kristin howard, recently named doctor of the year at newton wellesley hospital in massachusetts. Authorities say lit up on alcohol and pills howard prescribed to herself -- she was caught on tape in november tearing out of a supermarket parking lot. Howard has pleaded not gui dui and charges. If the rate of substance abuse in america is around 7% to 10%, why do we think it's lower for doctors? Reporter: In fact, nurse brown says the most honest portrayal of real life health care is -- of all things -- "nurse jackie," about a pill-popping e.R. Nurse. And it's not like it's easy for patients to find out for themselves how good or bad their doctor may be. Nurse brown says outright dece is rampant. Often the doctor is promising the family that we'll do x, and that will make all the difference and they'll get better. And we actually know that that's very unlikely ue. Reporter: Here's something else no one will tell you. The real reason you have to wait so long in that emergency room. Hospitals really are not looking to attract people into their emergency rooms. So, when you wonder why the wait in an emergency room is six or ten hours, it's not accidental. It's kind of by design. Because that is a population that just does not allow a hospital to be profitable. Reporter: Ah yes, the profit motive. Makary says it creates all kinds of conflicts of interest, leading doctors to prescribe more expensive drugs and even perform unnecessary procedures. If you do an operation you will go home with $1,000 or $2,000 more than if you didn't do the operation. Reporter: So the incentive is to operate? The incentives are huge. 20% to 30% of all procedures, tests, medications in health care are unnecessary. Reporter: Makary says he'll keep confessing the sins of his profession until everyone in medicine is held accountable for the mistakes they make. Reporter: How has writing this book made life for you in the hospital corridors? Well, there's a new movement to say, we've got to be open and honest about our serious problems and deficiencies in health care. And they have very little tolerance for b.S. When they see something that doesn't look right, they call people out.
This transcript has been automatically generated and may not be 100% accurate.