Adult Health Nursing–I forms a vital foundation in the professional journey of every nursing student. As adult patients constitute a major proportion of healthcare recipients, it becomes essential for learners to understand the wide spectrum of health conditions, therapeutic interventions, and nursing responsibilities involved in adult care. This book/module for B.Sc Nursing III Semester has been developed with the aim of providing students with an in-depth understanding of the principles and practices related to adult medical–surgical nursing.