I just took step three of the national board exams – the final in a series that all U.S. physicians must pass to practice medicine unsupervised. The two day exam, composed of multiple choice questions and simulated patient cases requiring free-text answers, brought up subjects that we haven’t thought about since medical school (Sick children? Terrifying.) The test also shed some light into how doctors think under pressure and why reigning in health care costs remains an uphill battle.

I have to give credit to the test’s authors. In the introduction to the simulated cases, they make a point of writing that over-testing and over-treating carry penalties (both on the test and for patients in real life). If a patient comes in with a headache and you order a brain biopsy straightaway, point deducted!

But as I went through practice cases in the days before my test, I found an unmistakable bent towards ordering lots of tests upfront, sometimes unnecessarily: I read that a young woman is seeing me in the office for abdominal cramping brought on by stress as well as bowel movements that cycle between diarrhea and constipation. She has no warning signs that make me worry about a serious illness like cancer or autoimmune disease. She has classic irritable bowel syndrome (IBS), I decide, and I (virtually) counsel her to that effect.

When I review my answers for this practice case I learn that yes, she has IBS, but that I was still expected to check for parasites and making her collect all of her bowel movements over a three day period to look for undigested fat (a sign of pancreas dysfunction, among other things). I balk and move on. By the end of my test preparation, I’d gotten into the habit of rapid-typing as many relevant tests as I could think of because I knew it was expected of me and to hedge against the possibility of being wrong.

I recognize that it’s difficult to capture the nuances of clinical practice and the tincture of time in a standardized test. This one does a pretty good job all considering. But the expectation and practice of over-testing is mirrored in the real world all too often, particularly on busy call nights: One of our patients had a drop in his blood count, most likely because he’d lost some blood and received intravenous fluids (diluting his blood) during surgery the night before. The intern presenting his case reported that she’d ordered a whole battery of tests to evaluate his anemia: iron studies, vitamin B12, folic acid levels, the list went on. I gently suggested that a repeat blood count later that day would have sufficed.

There are some clinical situations in which throwing on a bunch of tests and treatments at once is the right thing to do (One of them is sepsis or widespread infection. Many involve the emergency room). But much of the time, we are better served by clinical elegance: only ordering tests that will inform what you do next. We have clinical guidelines to help us with this. We also need to incorporate these conversations better into our clinical training and practice.

One trick I shared with this intern and others that applies to practicing medicine (and, for now, to board exams): If you think of an obscure but unlikely cause for a patient’s symptoms and the expensive test that you need to diagnose it, write it down and share your idea with the medical team but don’t place the order. That way you get credit for the thought process without hiking up the bill.

Ishani Ganguli is a journalist and an internal medicine-primary care resident who blogs at The Boston Globe’s Short White Coat, where this article originally appeared.