Although the entire evolution of life is an adaptation right from the coming-together of the elements and reaching to human life as we know today, the realization of the adaptation biology as a discipline is relatively recent. Furthermore, subcellular basis of gradual adaptation of body systems in stressful conditions is still a greate mystery of biology. The present book attempts to fill that gap. It is known that such an adaptation not only increases tolerance of the body to that given stress but also to other challenges. A complete knowledge of this cross protection needs to be defined and exp;oited to improve patient care. The book includes chapters describing subcellular adaptations; adaptation to different stresses as well as to lifestyle and environment. Although for an easy reading the information has been grouped under the sub-heading: Current Trends, the book represents a common continuum of adaptations. The therapeutic value of the understanding of the science of adaptation has also been described in several chapters. Examples of cross adaptations are also provided, where repeated exposure to one stinulus may ptentialyy be used in the treatment as well as prophylaxis of different diseases.The present book will be of great interest to all biologists, physiologists, pharmacologists and physicians interested in the application of the biology of adaptation in the improvement of health.