The Mystery of Sleep by Meir Kryger

Reviewed by Ian Lipke

The Mystery of Sleep is one of those books that the reader comes back to time and again to discover something new and enriching. It is a book that for most folk never becomes boring, but retains its freshness at each reading. Written by one of the leading lights in understanding the significance of sleep, “it usefully outlines the current state of knowledge of sleep science in humans” (Groopman). Meir Kryger is a professor in the Yale School of Medicine and chief editor of a very widely used sleep medicine textbook Principles and Practice of Sleep Medicine. He is recognised as a global authority on sleep.

In describing the different facets of sleep from birth to retirement and beyond, Kryger demonstrates a superior knowledge of his subject.  His book consists of four parts: One looks at sleep in the abstract, Two at identifying sleep problems, Three at ‘can’t sleep, can’t stay awake’, and Four at ways of getting help. Each section is a rigorous and comprehensive view.

The first part considers the reasons why we sleep at all, why we need sleep. These reasons are then considered  at various stages in the life cycle with particular focus on the reproductive years, pregnancy and post partum, and during menopause and andropause. Kryger admits at the outset that sleep study is so new (it began as a discipline in the 1970s) that the great learning curve is still ahead.  It seems acceptable that our sleep requirements are determined by our genetic blueprint and that without sleep, we die. It is speculated, or in some circles, accepted that we sleep to allow the removal of waste products from our brains, the conservation of energy, the restoration of important bodily functions and the repair of damaged tissues (5).

Kryger describes a wake gauge that indicates when we need to sleep. The wake gauge in the brain  measures the amount of a chemical called adenosine, which is involved in the transfer of energy in the body. The longer one remains awake the more concentrated becomes the adenisone. A measure of good quality sleep is the extent to which a person awakes feeling fresh and anticipatory of the day ahead. Using a case study as a guide to the description that follows, Kryger develops ideas on the amount of sleep that is required at each stage of the life cycle.

Part Two elaborates upon the identification of whether individuals actually have a sleep problem. He considers how the patient might explain their problem so that the medical practitioner can understand what’s going on. He uses a case study of a tired man with cancer. In this case the man had complained of tiredness for two years, his doctor treating him for depression or ignoring his reported behaviours completely. Only when the wife insisted on clinical tests was it revealed that he had colon cancer.  This is a huge section that treats in detail the problems of the insomniac, the issues facing the partners of a non-sleeping individual, the night owl, the graveyard shift, travelling east and travelling west, and so on.

Part Three gives a comprehensive explanation of the medical conditions that affect sleep. These are complex issues that the expert attempts to describe in the language of the educated non-expert. He describes and explains, restless legs syndrome, sleep apnoea, narcolepsy, abnormal behaviour when dreaming , bruxism, and night sweats. He specialises in another chapter with specific relevance to Alzheimer’s Disease, headaches, Parkinson’s – all attributes of the nervous system. A similar comprehensive account of sleep issues associated with each of the body’s systems follows.

The final section, and for many the most valuable section, discusses the issue of getting help. When reading this particular area of the book I was struck with the notion that Kryger, knowing how critical, how important this section of the book is, had geared himself to giving of his best. He  reports on the necessity of seeking reputable people in which the patient can receive professional help. He writes of the types of sleep studies and clarifies what each type of study can and cannot do. He explains what to do and what to expect if a sleep problem is mooted. Another section  looks into cognitive therapy, sleep hygiene, and self-monitoring, and taking responsibility. Another chapter takes up the issue when pills need to be part of the treatment. Medical conditions that are treated with drugs are then identified and a brief, but adequate explanation of the drug in use and what to expect of it follows. He finishes with a neat summary that affirms the need in all of us for restful sleep.

The publication contains a bibliography of relevant studies written in plain English and an index.

This s a very impressive piece of work. Sleep is a very complex phenomenon and, just as he has done in a previous publication, Kryger reveals its secrets to an avid readership. A highly recommended explanation of the subject, sleep.


The Mystery of Sleep


By Meir Kryger

Yale UP

ISBN: 978-0-300-23453-4

344pp; $32.99

To order a copy of Mystery of Sleep: Why a Good Night’s Rest Is Vital to a Better, Healthier Life at the Footprint Books Website with a 15% discount click here  or visit


Please use discount voucher code BCLUB18 at the checkout to apply the discount.




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