Functional Unit – Making a Diagnosis

Making a Diagnosis

The great variation in medicine can be learned only from the one true teacher of disease that the student of medicine encounters – the patient. And it is a lifetime’s work.

“You fill me with interest,” said Holmes. “Pray give us the essential facts from the commencement, and I can afterwards question you as to those details which seem to me to be most important…”
Sir Arthur Conan Doyle

We are nearing the end of our system of medicine. You now have most of the pieces of the puzzle. You have learned how to think like a doctor, you know how to analyse a medical problem and you know how to produce a useful list of differential diagnoses using a functional unit and a sieve.

However there is still the task of actually making a diagnosis. At medical school, you are taught that this is straightforward. All you have to do is collect all the right clues from a patient and logically put them together. The clues are only found in a few places: mostly in the history, partly in the examination and sometimes in an investigation.

In real medical life, diagnosis can be an enormous challenge. Senior clinicians may seem to diagnose effortlessly, but learning about all the different clues in medicine and how to put them together takes many years, much study and much practice. And even once we have a diagnosis in mind we can’t always be sure of it. “Probability is the rule in life,” said Osler, “especially under the skin.”

Moreover, no two patients with a disease will give the same manifestation. Each patient has a different narrative and presents in their own unique way. Some can’t give any history at all, while others give far too much history. And every patient has their own personality, cultural, lifestyle, genetic and spiritual factors thrown into the medical mix. But herein lies the great joy of being a lifelong student of medicine.

There is therefore only one way to learn to diagnose – bring your systems and methods to the bedside, and start to practice. Good luck!

The great variation in medicine can be learned only from the one true teacher of disease that the student of medicine encounters – the patient. And it is a lifetime’s work.