Why We Sleep: The New Science of Sleep and Dreams

Sleep is one of the most important aspects of our life, health and longevity and yet it is increasingly neglected in twenty-first-century society, with devastating consequences: every major disease in the developed world - Alzheimer's, cancer, obesity, diabetes - has very strong causal links to deficient sleep.

In this book, the first of its kind written by a scientific expert, Professor Matthew Walker explores twenty years of cutting-edge research to solve the mystery of why sleep matters. Looking at creatures from across the animal kingdom as well as major human studies, Why We Sleep delves into everything from what really happens during REM sleep to how caffeine and alcohol affect sleep and why our sleep patterns change across a lifetime, transforming our appreciation of the extraordinary phenomenon that safeguards our existence.

"Startling, vital, a life raft."
Guardian

"A neuroscientist shows how a good night's shut-eye can make us clever, more attractive, slimmer, happier, healthier and ward off cancer... it's probably a little too soon to tell you that it saved my life, but it's been an eye-opener."
Mark O'Connell, Guardian

"Passionate, urgent...it had a powerful effect on me."
Rachel Cooke, Observer

"Compelling and utterly convincing... you'll never think of your bedtime in the same way again."
James McConnachie, The Sunday Times

“Why We Sleep: The New Science of Sleep and Dreams” by Matthew Walker is a groundbreaking exploration of the vital role of sleep in human health, cognition, and emotional well-being. The book combines scientific research, case studies, and practical advice to explain why sleep is not optional, but essential for survival, learning, and mental resilience.

Walker examines how sleep affects memory, creativity, immune function, and emotional regulation, revealing the consequences of chronic sleep deprivation on physical and mental health, including increased risk of Alzheimer’s, cardiovascular disease, obesity, and depression. He also explores the different stages of sleep, including REM (rapid eye movement) and deep sleep, and explains how dreams play a critical role in processing emotions and consolidating memories.

The book addresses societal factors that interfere with healthy sleep, such as work schedules, artificial lighting, and modern technology, and offers evidence-based strategies for improving sleep quality, including maintaining regular sleep schedules, optimizing the sleep environment, and managing caffeine and alcohol consumption.

“Why We Sleep” is both a scientific deep dive and a practical guide, providing readers with a clear understanding of how sleep shapes every aspect of life. It emphasizes that prioritizing sleep is one of the most powerful and accessible ways to enhance physical health, mental clarity, and overall well-being.