Defining disease according to its causes would improve our understanding of medicine.
Professor Sir John Bell, regius professor of medicine at Oxford University and president of the Academy of Medical Sciences, says that if we were able to redefine disease according to its true causes this would transform our understanding of medicine and improve diagnosis and treatment for patients.
Delivering this year’s Harveian Oration at the Royal College of Physicians, he outlines how, in the absence of evidence as to the underlying causes of diseases, they have often been named after symptoms or clinical presentation, and describes how this has impeded progress:
For most of the history of medicine, scientific principles have not enlightened the definition of disease. Instead, disease has been described and understood based on the evidence available to clinicians – predominantly the clinical symptoms and signs they elicited from the patient. Only in the past 150 years has disease begun to be characterised based on aetiology and mechanisms…
…Poor definitions impede accurate prognosis as well as early detection and prevention. The failure to understand fundamental events responsible for causality accounts for many of the limitations associated with modern clinical practice.
Mapping of the human genome has now brought great progress in identifying the genes associated with particular diseases, and has for the first time enabled us to identify the mechanisms for the development of those diseases. In addition, this genetic understanding of disease pathways can now allow us to subdivide diseases so that the role of environmental events can be more easily defined.
Sir John highlights the fields of microbiology, virology and parasitology, where clear understanding of causes and mechanisms have transformed our understanding of diseases and our subsequent ability to treat and prevent them. These include viral infections, the various forms of hepatitis, and cervical cancer.
Although historically progress to redefine disease has been slow, Sir John ends his Oration with a message of hope, as he believes that recent studies have accelerated the path, and that within our lifetime we will uncover key mechanisms for most common diseases:
There have been few occasions in the history of medicine where such opportunities exist to totally transform both our understanding of disease and the way we practise medicine. The potential for scientific discovery and the health of patient with virtually every form of disease could now be realised as we continue this systematic effort to redefine disease.
- William Harvey, the eminent 17th Century physician who discovered the circulation of the blood, gave an indenture to the RCP in 1656 for an annual dinner to encourage friendship between Fellows and Members of the College at which there should be an oration 'with an exhortation to the Fellows and Members of the said College to search and study out the secret of Nature by way of experiment'. The College continues the tradition by inviting a leading doctor or scientist to give the Oration on issues relating to his or her own field of work.