This book titled Endocrinology in Internal Medicine: Hormonal Disorders and Treatment offers a comprehensive exploration into the crucial role that endocrinology plays within the broader field of internal medicine. It serves as an essential academic and clinical guide for medical students, residents, practicing internists, and endocrinologists, aiming to bridge the understanding between complex hormonal imbalances and their systemic implications. The book delves into the physiological mechanisms of hormone production, secretion, and regulation while closely examining the pathophysiological basis of various endocrine disorders. It presents a clear and detailed approach to the diagnosis and management of a wide array of hormonal diseases that often intersect with other internal systems, thereby emphasizing the interdisciplinary nature of internal medicine. Each chapter is structured to provide a deep understanding of specific endocrine glands such as the pituitary, thyroid, adrenal glands, pancreas, and gonads, explaining their functions and the disorders associated with them. Common and rare conditions alike, including diabetes mellitus, thyroid dysfunction, adrenal insufficiency, Cushing’s syndrome, polycystic ovary syndrome, and osteoporosis, are discussed in a clinically relevant manner. The book integrates case-based learning and evidence-based guidelines to support clinical decision-making and patient management. It also highlights the importance of hormonal feedback mechanisms, diagnostic strategies including laboratory and imaging techniques, and individualized treatment plans ranging from pharmacological therapy to surgical interventions. This book stands as a valuable resource for those involved in the care of patients with hormonal disorders.