The end of the differential diagnosis
April 14, 2021
A differential diagnosis is a process, a mental process, that one is taught in medical school in order to facilitate understanding and trying to figure out what’s wrong. The body of information one uses in medical school has a lot to do with how your differential diagnosis is applied.
If someone has pain in the head, where is the pain coming from?
- Is it eye strain?
- Is it an ear infection?
- Is it a brain tumor?
- Is it a stroke?
- Is it a parasite in your head?
These are six or seven different suggestions that can occur. One can have an inflammatory arterial disease. Another problem could be rheumatoid arthritis. In other words, there should be a differential diagnosis for shoulder pain, for neck pain, and back pain. Differential diagnosis is going through a list of what’s common and what’s not common.
We have a saying in medicine, “When you hear hoof beats, you don’t think of zebras, you think of horses.” But common things are common, and you must go with that first.
Generally, one disease causes a myriad of symptoms. You can’t say you have five different diagnoses, when one thing is a problem. I know I’m being a little bit generic about that, but the differential diagnosis should be taught to medical students and used when one gets into your professional training, whether it be internal medicine, spine surgery, orthopedics, or neurosurgery.
A perfect example is chest pain. What’s causing the chest pain? Is the chest pain coming from lack of blood flow to the heart where the heart is painful, or is it heartburn, or is it an ulcer? Or even is it painful where the ribs attach to the sternum? We call that costochondritis, and it is an arthritic condition. There are many different causes of symptoms, but physicians go with screening tests without much thought. That is what the MRI does. To screen people for something that is not justified clinically.
If one is not examined and one is not listened to, and the doctor doesn’t pay attention, it doesn’t go through in his or her mind cognitively what is going on, they are going to miss it. That’s why a lot of people have unnecessary back surgeries. That’s why a lot of women have unnecessary hysterectomies. That’s why a lot of people have many tests that are irrelevant because they’re hunting and seeking for a diagnosis rather than clarifying with a history and physical exam.
This is what is lacking in today’s medical climate. Doctors do not cognitively put together a differential diagnosis for any set of symptoms before they order any kind of screening test.
For further reading on this topic, I strongly recommend this recent article which provides a well written perspective on differential diagnosis, medical skills and how corporate medicine and insurance companies have tried to universally diminish it.
https://www.kevinmd.com/blog/2021/03/an-ode-to-the-differential-diagnosis.html
