Book excerpt: Hair is a major component of the body's tissue system that contributes to the individual's make up and confers a large degree of personal identity. Apart from its visible façade, hair also has a functional role. It has an unique structure and complex molecular development. The very nature of hair makes it a suitable marker for the prognosis of disease. Hair can also be used to screen for toxins and changes in the diet. However, there are currently no suitable publications available that describe hair in a rational scientific context. This handbook provides an academic approach to hair in health and disease. Divided into five sections the Handbook of Hair in Health and Disease provides an insight into hair growth and loss, molecular and cellular biology of hair, dietary toxicity and pathological history, diseases and treatments of hair, as well as shampoos and conditioners. Unique features of each chapter in this volume include relevant and useful 'Key facts' which highlight interesting or important findings of the specific subjects and 'Summary points' that will give a clear overview of the subjects treated in each chapter. The Handbook of Hair in Health and Disease will be essential to a variety of users, such as trichologists, doctors and nurses and all those interested or working within the area of hair health. This includes nutritionists and dieticians, scientific beauticians, health workers and practitioners, college and university lecturers and undergraduate and graduate students.