The primary goal of this textbook is to provide a comprehensive overview of the etiology, pathogenesis, clinical features, treatment, and prevention of internal diseases, tailored to the curricula of secondary medical education programs. It offers up-to-date insights into diagnostic and therapeutic methods for internal organ disorders, including detailed descriptions of essential diagnostic procedures that nurses must perform when caring for patients in a hospital setting. The book also covers first aid techniques for acute internal conditions, poisoning, intoxications, heatstroke, sunstroke, and more. Written in accordance with the program approved by the Ministry of Health of the USSR, this textbook is intended for students in nursing departments of medical colleges.