Definitions of chronic disease need to be more patient centred

Early, small abnormal changes should be defined as disease only if there are effective interventions that can make an important difference to patients, argue Zu-Yao Yang and Jin-Ling Tang The proposal for new diagnostic criteria for hypertension in November 2022 caused heated debate in China. The recommendations, from a guideline group of leading Chinese clinicians,1 followed changes to the American hypertension guideline in 2017 to reduce the cut-off blood pressure for diagnosing hypertension from 140/90 mm Hg to 130/80 mm Hg.2 Adoption of this new diagnostic cut-off value for the Chinese population would have created around 350 million new patients with hypertension and increase the total number with the diagnosis by 130%.3 The new recommendation quickly caused intense nationwide debates, and the National Health Commission finally said no to it.4 The controversy over the diagnostic criteria of hypertension, which has also occurred for other non-communicable diseases, raises a fundamental question for medicine: what should count as a chronic disease? Historically, disease was known as sickness or illness, which is defined and diagnosed according to symptoms and signs and is in essence the patient’s current experience of their health. In some sense, it is patients who decide what a disease is. This has all been changed since medicine started coupling with modern science and technology. Over the past few decades, physiological, biochemical, histological, and imaging technologies have greatly extended our ability to “see” within the body. This led to the discovery that disease begins with small changes at the cellular, molecular, biochemical, or physiological level and that symptoms and signs become apparent only later, when these changes …