3 a.m. was the time I witnessed a case that changed the way I think.
He came in complaining of epigastric pain. He had eaten a whole chicken that night, a heavy meal, a simple explanation. The residents in the emergency department, exhausted at the end of a 15-hour shift and overwhelmed by the crowd of patients around them, gave him an IV H2 blocker and left him for monitoring. He said he felt better. That was where there was no coming back. Confident in their diagnosis of indigestion, the residents discharged him.
A few hours later, the scene was like a Greek tragedy. The man carried by the arms of his own family, his arms hanging limp, not moving, not breathing, while the screams of his wife and children played as the disrupted background music to something no one should ever have to witness. He had suffered a myocardial infarction. Nobody had ordered an ECG. Nobody had thought about his heart. The chicken had already answered that question for them.
This was not ignorance. This was not laziness. This was a cognitive bias, and it has a name.
Anchoring is the tendency to rely too heavily on the first piece of information we encounter when making a decision. The brain uses that initial detail as a baseline (an anchor) and builds every subsequent judgment on top of it. In our story, “I ate a whole chicken” became the anchor. Everything that followed (the assessment, the diagnosis, the treatment, the discharge) was built on that single sentence from a man who was dying.
What makes anchoring dangerous is not that it leads us to wrong information. It leads us away from the right information. Once the brain accepts an anchor, it does something called positive hypothesis testing; it selectively searches memory for everything that supports the anchor and suppresses everything that contradicts it. The residents weren’t ignoring the possibility of MI. Their anchored minds simply never surfaced it.
A landmark 1997 study by Strack and Mussweiler demonstrated this mechanism precisely. Participants exposed to a high financial anchor were significantly faster at recognizing luxury-related words; their brains had been primed to find supporting evidence. The anchor doesn’t just influence the conclusion. It shapes what the mind is even willing to look for.
In a crowded emergency department at 3 a.m., with a patient who has a story that fits, that mechanism is almost invisible. And that invisibility is what makes it lethal.
The rule I gave myself after that night: When a patient tells me why they have epigastric pain, I listen. Then I order the ECG anyway. The story is where the thinking starts, not where it ends.
He told us he ate a whole chicken. His heart had other plans. We just never asked it.
Ahmed Azab is an internal medicine physician.
