The Age of Diagnosis

THE MUST-READ BESTSELLER AND BOOK OF THE YEAR IN THE GUARDIAN , SUNDAY TIMES , FINANCIAL TIMES , ECONOMIST , NEW SCIENTIST AND MORE 'Revelatory. Slices through the contradictions.' - CHRIS VAN TULLEKEN 'So well-written... critically important.' - RANGAN CHATTERJEE 'A doctor's brilliant study of the dangers of overdiagnosis' - GUARDIAN From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and transforms how we think about illness and health. Chosen as a 'brilliant book to read this summer' by the GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES 'Exceptional. Chapter by brilliant chapter, it raises fundamental questions we should all be asking.' - NEW STATESMAN *As heard on Radio 4 Book of the Week, Today, Good Morning Britain, Sky News and more.*

THE MUST-READ BESTSELLER AND BOOK OF THE YEAR IN THE GUARDIAN , SUNDAY TIMES , FINANCIAL TIMES , ECONOMIST , NEW SCIENTIST AND MORE 'Revelatory. Slices through the contradictions.' - CHRIS VAN TULLEKEN 'So well-written... critically important.' - RANGAN CHATTERJEE 'A doctor's brilliant study of the dangers of overdiagnosis' - GUARDIAN From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and transforms how we think about illness and health. Chosen as a 'brilliant book to read this summer' by the GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES 'Exceptional. Chapter by brilliant chapter, it raises fundamental questions we should all be asking.' - NEW STATESMAN *As heard on Radio 4 Book of the Week, Today, Good Morning Britain, Sky News and more.*

'Slices through the confusion with grace and compassion. I cannot say good enough things about it.' - CHRIS VAN TULLEKEN 'A brilliant study of the dangers of overdiagnosis' - GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES , best books of 2025 From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and reframes how we think about illness and health.

'Slices through the confusion with grace and compassion. I cannot say good enough things about it.' - CHRIS VAN TULLEKEN 'A brilliant study of the dangers of overdiagnosis' - GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES , best books of 2025 From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and reframes how we think about illness and health.

***THE INSTANT SUNDAY TIMES BESTSELLER*** A BEST BOOK OF 2025 IN THE TIMES , SUNDAY TIMES , FINANCIAL TIMES, GUARDIAN , ECONOMIST, OBSERVER, LONDON STANDARD, NEW STATESMAN AND IRISH TIMES 'Revelatory. Slices through the contradictions that had tied me in knots.' - CHRIS VAN TULLEKEN 'So well-written. Raising awareness of something that is critically important.' - RANGAN CHATTERJEE From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and reframes how we think about illness and health. A RADIO 4 BOOK OF THE WEEK 'A brilliant study of the dangers of overdiagnosis' - GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES *As heard on Good Morning Britain, Sky News, Radio 4 Today and more.*

***THE INSTANT SUNDAY TIMES BESTSELLER*** A BEST BOOK OF 2025 IN THE TIMES , SUNDAY TIMES , FINANCIAL TIMES, GUARDIAN , ECONOMIST, OBSERVER, LONDON STANDARD, NEW STATESMAN AND IRISH TIMES 'Revelatory. Slices through the contradictions that had tied me in knots.' - CHRIS VAN TULLEKEN 'So well-written. Raising awareness of something that is critically important.' - RANGAN CHATTERJEE From autism to allergies, ADHD to long Covid, more people are being labelled with medical conditions than ever before. But can a diagnosis do us more harm than good? The boundaries between sickness and health are being redrawn. Mental health categories are shifting and expanding all the time, radically altering what we consider to be 'normal'. Genetic tests can now detect pathologies decades before people experience symptoms, and sometimes before they're even born. And increased health screening draws more and more people into believing they are unwell. An accurate diagnosis can bring greater understanding and of course improved treatment. But many diagnoses aren't as definitive as we think. And in some cases they risk turning healthy people into patients. Drawing on the stories of real people, as well as decades of clinical practice and the latest medical research, Dr Suzanne O'Sullivan overturns long held assumptions and reframes how we think about illness and health. A RADIO 4 BOOK OF THE WEEK 'A brilliant study of the dangers of overdiagnosis' - GUARDIAN 'Compassionate and bracingly independent thinking' - THE TIMES *As heard on Good Morning Britain, Sky News, Radio 4 Today and more.*

From a neurologist and award-winning author of The Sleeping Beauties , a meticulous and compassionate exploration of how our culture of medical diagnosis can harm, rather than help, patients I'm a neurologist. Diagnosis is my bread and butter. So why then would I, an experienced medical doctor, be very careful about which diagnosis I would pursue for myself or would be willing to accept if foisted upon me? We live in an age of diagnosis. The advance of sophisticated genetic sequencing techniques means that we may all soon be screened for potential abnormalities. The internet provides a vast array of information that helps us speculate about our symptoms. Conditions like ADHD and Autism are on the rapid rise, while other new categories like Long Covid are driven by patients themselves. When we are suffering, it feels natural to seek a diagnosis. We want a clear label, understanding, and, of course, treatment. But is diagnosis an unqualified good thing? Could it sometimes even make us worse instead of better? Through the moving stories of real people, neurologist Suzanne O'Sullivan explores the complex world of modern diagnosis, comparing the impact of a medical label to the pain of not knowing. With scientific authority and compassionate storytelling, she opens up new possibilities for how we might approach our health and our suffering.

From a neurologist and award-winning author of The Sleeping Beauties , a meticulous and compassionate exploration of how our culture of medical diagnosis can harm, rather than help, patients I'm a neurologist. Diagnosis is my bread and butter. So why then would I, an experienced medical doctor, be very careful about which diagnosis I would pursue for myself or would be willing to accept if foisted upon me? We live in an age of diagnosis. The advance of sophisticated genetic sequencing techniques means that we may all soon be screened for potential abnormalities. The internet provides a vast array of information that helps us speculate about our symptoms. Conditions like ADHD and Autism are on the rapid rise, while other new categories like Long Covid are driven by patients themselves. When we are suffering, it feels natural to seek a diagnosis. We want a clear label, understanding, and, of course, treatment. But is diagnosis an unqualified good thing? Could it sometimes even make us worse instead of better? Through the moving stories of real people, neurologist Suzanne O'Sullivan explores the complex world of modern diagnosis, comparing the impact of a medical label to the pain of not knowing. With scientific authority and compassionate storytelling, she opens up new possibilities for how we might approach our health and our suffering.