The Third Edition of this popular book brings up to date the material that so many readers found helpful in the previous editions. The text has been revised and reorganized with current chapters focusing on the history of cortisol use, sources of confusion regarding cortisol therapy, the significance of normal adrenocortical function, generally accepted uses of physiological dosage, viral infections, miscellaneous clinical conditions, and future directions for research and therapy. The author provides explanation and confirmation of the rationale for the effectiveness and safety of the uses of physiological dosages of cortisol in the treatment, not only of patients with rheumatoid arthritis and other autoimmune disorders, but also of patients with chronic allergies, chronic fatigue syndrome, gonadal dysfunction, infertility, shingles, acne, hirsutism, respiratory infections, and other less common disorders. It is a known fact that the influenza virus attacks the human body by impairing the production of the adrenocorticotropic hormone (ACTH), which, in turn, impairs the production of cortisol; the only hormone that is absolutely essential for life. In addition, within the past two years, a new infection has developed in central China and has been labeled Severe Acute Respiratory Syndrome (SARS). The ACTH hormone and the SARS epidemic is addressed, and it is hoped that this type of cortisol therapy will not only be helpful in the treatment of the various disorders mentioned but will lead to a better understanding of the factors that contribute to the development of these disorders and ultimately contribute towards their prevention.