At a personal level, everyone recognises the importance of good quality sleep. From a medical perspective, however, only recently has the potential adverse impact of a disordered sleep–wake cycle on cognitive, mental and even physical health been realised. The consequences of excessive daytime sleepiness are also increasingly defined, especially with respect to driving and other potentially dangerous activities. Perhaps surprisingly, the precise biological reasons why every animal has a basic need for regular sleep are still speculative and the fascinating state of rapid eye movement (REM) sleep remains a particular enigma. However, it is abundantly clear that sleepiness is a true drive state and, ultimately, as important as hunger or thirst for optimal health and survival. Partly because it cuts across numerous more established specialities, the emerging discipline of sleep medicine remains in its infancy and is generally poorly addressed in medical schools. As a consequence, many physicians in primary and secondary care lack confidence in addressing sleep-related symptoms, despite significant advances in our understanding and treatment options for the majority of sleep disorders over the last decade.
A further confound is a widely held and mistaken belief that sleep disorders invariably require complex and expensive techniques for confident diagnosis. With the exception of sleep-related breathing disorders, the majority of sleep disorders can actually be adequately managed without an absolute need for detailed investigations. This book has been written as a primer for understanding the fascinating phenomenon of sleep and its commoner disorders. The aim has been to provide a readable text for non-specialists, covering the full range of recognised sleep disorders that might present to general physicians and sleep clinics. Throughout, it is emphasised that a full sleep–wake history, potentially corroborated by close family members, together with a basic knowledge of sleep neurobiology, will usually allow an accurate diagnosis and potential treatment options. The full range of diagnostic sleep investigations is also discussed in some detail, outlining when they are appropriate but also highlighting pitfalls in interpretation. Of course, it is often difficult to know whether sleep-related symptoms reflect a defined disorder or simply result from social or psychological factors; grey areas undoubtedly remain. However, symptomatic ‘red flags’ are highlighted which may indicate the need for more specialist attention. A particularly difficult area in sleep medicine is the scarcity of a controlled evidence base to guide treatment protocols. As an inevitable consequence, the reader should be aware that many suggestions for medications mentioned in this text are personal recommendations, based largely on anecdotal evidence. Furthermore, it should be noted that it is rare for a drug to have a formal licence for use in sleep medicine. Sleep clinics, at least in the United Kingdom, are increasing in numbers but remain variable in their ability to address the whole gamut of sleep disorders.