What does the diagnosis mean?
‘Diagnosis’ means the cause of a health problem. The main role of a doctor is to decide upon the diagnosis.
In this article, we will expand more on what is a diagnosis.
To be able to make a diagnosis, doctors are trained for 4-6 years in the UK. Most of the training is learning:
- How to recognise ‘disease patterns’ (via questioning patients and examination); and,
- Long lists of causes of those patterns (with the most common on top).
An example of a ‘disease pattern’ is: more frequent urination (weeing) with burning, combined with being tender in the lower tummy. This is a common pattern of a urine infection.
Philosophical basis of making a medical diagnosis
Much of this ‘Western Medical method’ is based on Cartesian thinking – i.e. derived from Rene Descartes, the 17th Century French philosopher and mathematician – as explained here. It is a good way of thinking, in that it leads to the search for the pathological cause of a presentation. But it has problems as well, e.g. it can lead to:
- Over-certainty to the initial diagnosis (which may be incorrect), when a wider differential (alternative) diagnosis would have been better. Then false information is passed on to the next doctor, who copies it; or
- Fitting (or cramming) the diagnosis (and therefore treatment) into a ‘too tight’ box that tries to explain everything in one simple common diagnosis; not allowing for:
- more than one linked diagnoses – e.g. CCF secondary to infective endocarditis, both of which need treating;
- more than one separate diagnoses – the frail elderly may defy Occam’s Razor and have more than one diagnosis;
- a rare or new disease;
- a change of direction later.
Cartesian thinking is also part of the basis for what is called the ‘Scientific Method’, of which Medicine is part.
Expressing diagnostic uncertainty – an example
It is OK to be not sure of the initial diagnosis. This is often the reason for hospital admission. Here is an example of three ways of handling the same patient.
A 26 year lady, on the oral contraceptive pill, presents with rapid onset L sided pleuritic chest pain. There is nothing to find on examination. Three doctors came up with three different diagnoses, plans and outcomes.
Doctor A. Diagnosis: ‘Trop T negative chest pain, await senior review’. No best ward indicated to nurses. Ends up on geriatric ward, which frightens her.
Doctor B. Diagnosis: ‘PE. Start SC heparin’. Did not request further investigation or specialist review. No best ward. Ends up in surgical ward, which confuses her, and no medical team reviewed her till Day Six, after the Easter Bank Holiday weekend.
Doctor C. Diagnosis: Pleuritic chest pain ?cause. ?PE ??Pneumonia ??Pneumothorax. Do ABG. D-dimer, CTPA (both requested). Chest opinion (requested). Chest ward (requested). SC Heparin and antibiotics started.
Final Diagnosis: Recurrent Pneumothorax (made by chest registrar, on Day Three) due to Marfan’s Syndrome. A small pneumothorax was spotted in retrospect on the CXR (its OK that docs A, B and C missed it).
A more thorough history would have picked up previous episode as a child. A more thorough examination would have picked up her height (6ft 1in). But only Doc C put the patient in a position for someone else to make the diagnosis.
Conclusions
Doctor A was under-confident – and did not want to make any decision, practising defensive medicine
Doctor B was over-confident – and stuck to a single common diagnosis leading to the wrong treatment. He/she forced the diagnosis into a box, as PE seemed to fit simply
Doctor C was thorough and careful (noted the childhood history) and correct – but also expressed diagnostic uncertainty. This led to a good outcome.
Summary
We have explained what does the diagnosis mean. We hope you understand it better now.
