My nurse practitioner came to me with the case of a 40-year-old patient complaining about aches and pains from an auto accident. Just three days before, he had been released by the trauma center with instructions to see his family doctor. That turned out to be me. He was new to my practice. What impressed my nurse practitioner more than his injuries was the way he knocked the doctors and the hospital where he had been treated. Everything he said seemed negative, with a particularly hostile edge. "I wonder what he's going to say about us," my nurse practitioner said. So did I. An exam of the patient revealed some general soreness and a little extra tenderness in the abdomen. I ordered a CT scan. I wasn't all that worried about internal injuries. Still, the small chance of missing something on a dissatisfied patient was too big a risk for my professional comfort. His scan came back normal, as I expected. But doctors learn early to play defense. I've never been sued, but I've seen doctors accused of malpractice when there is a bad outcome, regardless of whether they seemed to have done anything wrong. There is an expectation after a patient does badly that the doctor should have ordered another test or done something else. But sometimes things go wrong no matter what you do -- or don't do. Defensive medicine is part of the cost of doing business, and also, unfortunately, a large part of the unnecessary expense of health care. In my experience, I'd estimate it accounts for 10% of the waste. Some days I think that's probably conservative. Unlike defensive driving where slowing down and being less aggressive saves lives, defensive medicine means doing more tests, ordering more consults from specialists and exposing patients to the risks of radiation, invasive tests and treatments. It transcends being cautious or careful for the patient's sake. It has everything to due with protecting the practice from the legal system. I try not to order expensive or risky tests to chase down minor lab or X-ray findings. Some physicians feel compelled to do this. One thing that we doctors hate almost as much as a faulty diagnosis is winding up in court to defend our decisions. Once a doctor has had his judgment questioned in a lawsuit, his documentation and test ordering will never be the same. A typical line of legal attack is that you didn't order a test or refer a patient to a specialist fast enough. A general surgical colleague used to handle elderly patients with higher medical risks. He was good at his job and never turned anyone away for lack of insurance. After being sued, he transferred many patients with problems he used to take care of himself to bigger hospitals for care. The change was expensive, adding ambulance or helicopter costs, and it delayed some surgeries. Another sign of the times can be found in patient files, which have become more suited to legal defense than medical communication. The modern medical chart often contains reams of normal data kept to satisfy auditors and show that doctors are comprehensive in taking a history and performing an exam. To ward off critics, we put in comments like, "The patient denies other complaints." Electronic medical records provide even more opportunities to pack in boilerplate entries. The notes from specialists about my patients are now four to five pages long, and I have to search for the nugget of useful information and advice, usually toward the end. Patients are defensive, too. They look up their symptoms on the Internet and then insist on testing and consultations for symptoms that can be safely observed and frequently go away on their own. What can we do? Building better relationships between doctors and patients would help, though that's a tall order given the brief visits that have become the norm. If you are going into the hospital, think about leaving your most confrontational family member at home. When the family questions every detail of care to the Nth degree, you're going to get more testing, more specialists poking you and more cost. If that type of evaluation and treatment is what you are after, most doctors will oblige. Just make sure to factor in the extra doses of radiation from scans, the extra medication you might be allergic to, and the extra procedures the specialist is likely to recommend. Speak up if you suspect a test is just being ordered to cover the doctor's derriere. The defensive among us will document your informed refusal and our estimation that your lack of compliance might hurt you. The rest of us would probably agree with you. Due to his schedule and the volume of email he receives, Dr. Brewer may not be able to respond to all reader email. He does participate in his forum, where readers are urged to post. His email address is email@example.com.