Systematic Reasoning
Frameworks matter more than memory when you’re standing in front of a sick patient at 3am. Take chest pain for example – common and high stakes!
The Chest Pain Framework
Chest pain is one of the most common acute presentations. It’s also one where the standard approach quietly fails you.
Most doctors hear “chest pain” and immediately start pattern-matching. Crushing and central? MI. Pleuritic? PE. Worse after food? GORD. The brain locks onto a diagnosis within seconds – and then stops looking.
This works most of the time. That’s what makes it dangerous. Because when it doesn’t work – when the dissection presents like an MI, when the PE mimics pleurisy, when the oesophageal rupture gets dismissed as reflux – the consequences are catastrophic.
The issue isn’t that you don’t know the causes. You do. The issue is that under pressure, your brain reaches for the first plausible answer and stops searching. There’s no built-in mechanism to check what you might be missing.
Two layers of thinking
The chest pain framework addresses this with two distinct tools that work in sequence.
The first is a rapid safety screen – a mnemonic that ensures you check for every time-critical diagnosis before you commit to a working differential. It takes under five minutes and it works even when you’re exhausted, because it’s designed for fast recall. It doesn’t require deep reasoning. It requires discipline.
The second is a full diagnostic tree – a structured framework that categorises every significant cause of chest pain into logical branches. Cardiac and non-cardiac. Then further subdivisions within each. This is where the real reasoning happens. Instead of pulling diagnoses from memory at random, you work through categories systematically, asking targeted questions at each branch point to include or exclude causes.
The mnemonic protects you from missing emergencies. The diagnostic tree gives you a thorough, organised differential. Together, they replace the “what am I forgetting?” feeling with a process you can trust.
You probably already use mnemonics. That’s not the same thing.
Most doctors have a handful of mnemonics they picked up in medical school or on the wards. Maybe you remember a few causes of chest pain grouped by a catchy acronym. Maybe you can list the reversible causes of cardiac arrest.
That’s useful. But it’s not a system.
Knowing a handful of causes isn’t the same as knowing what to do with them. A mnemonic gives you a list. It doesn’t tell you which diagnosis to consider first, what questions to ask at each step, how to weigh one possibility against another, or when to stop investigating and start acting.
A diagnostic framework does all of that. It takes the same clinical knowledge you already have and organises it into a sequence – so you’re not just recalling causes, you’re reasoning through them. There’s a difference between knowing that aortic dissection is a cause of chest pain and knowing exactly when and how to check for it in the middle of an assessment that’s pointing you toward something else entirely.
The mnemonic is one piece. The framework is the whole structure.
This isn’t a set of training wheels
There’s a common assumption that diagnostic frameworks are remedial – something for junior doctors who don’t know enough yet. A crutch to be discarded once you gain experience.
That’s not what this is.
The best consultants I’ve worked with all have frameworks. They might not draw them on paper or refer to them by name, but they have a structured way of thinking through presentations that ensures they don’t miss things – even when they’re tired, distracted, or dealing with something atypical.
The difference between them and a resident doctor isn’t that they’ve moved beyond structured thinking. It’s that their frameworks have become automatic. They’ve internalised them through thousands of cases until the structure runs in the background without conscious effort.
The problem for most doctors early in their career is that nobody makes this thinking explicit. You’re expected to absorb it through osmosis over years of clinical exposure. Some people do. Many don’t – and they blame themselves for it.
These frameworks don’t expire. You learn them once, you use them forever. The structure that helps you as an FY1 is the same structure running silently when you’re a consultant seeing your thousandth chest pain. The only thing that changes is how quickly it runs.
The sooner you learn them, the sooner every acute take gets easier.
What changes when you use it
You stop anchoring on the first diagnosis that fits. You stop shotgun-ordering investigations because you’re not sure what you’re looking for. You start communicating with seniors in a way that’s structured and specific – not “I think it might be cardiac” but a clear reasoning pathway that shows what you’ve considered and why.
The framework doesn’t make you faster by cutting corners. It makes you faster by removing the hesitation that comes from not having a system.
Get the Chest Pain Framework
The full Chest Pain Framework – including the rapid safety mnemonic and the complete diagnostic tree – is available as a free download alongside the A-E Assessment Guide.
This is one of fourteen.
The Acute Medicine Course teaches the same two-layer approach across 14 acute presentations – from dyspnoea and sepsis to electrolyte disturbances and delirium. Each one gives you both the rapid screen and the full diagnostic structure.
