What is disease? And why it’s a healthy question

Fresh research from Finland has again stoked the fires of debate over what constitutes disease and who warrants a medical label.1 The study in BMJ Open surveyed more than 3000 doctors, nurses, lay people, and politicians. It found high levels of agreement that conditions such as breast cancer and myocardial infarction were diseases but great disagreement about sexual difficulties, premenstrual problems, and other states of being. Surprisingly, the fictional motivational deficiency disorder2 was recognised as genuine, though by only a small number. Unsurprisingly, perhaps, doctors were slightly more likely than lay people to consider states of being as diseases.

Although diagnostic criteria so often seem certain and fixed, in reality there are, as this new Finnish study reminds us, many fascinating questions swirling around the hazy line dividing person and patient. Is being “at risk” of a disease really a disease itself? What degree of functional change, particularly if it’s part of normal ageing, …