In this publication a comprehensive overview on the pathophysiology and treatment of hyperhidrosis with a focus on the new therapy with botulinum toxin is given by renowned experts from Europe and the USA. In the first part the pathophysiology of hyperhidrosis, rare forms of sweating and their symptoms, as well as the different topical and surgical treatments for focal hyperhidrosis are discussed. The second part deals with botulinum toxin. Besides a historic survey of the drug the reader is introduced to the pharmacological particularities and the different modalities of treatment for focal hyperhidrosis. Complications and side effects of the therapy are presented as well. The final chapter is reserved for other dermatological indications like anal fissure and wrinkles. This book will be of special interest to dermatologists, neurologists and plastic surgeons who wish to inform themselves about working with botulinum toxin. The extensive background information included on the subject also makes it a practical guide for general practitioners and medical students.