In the book, the focus is on “The differential diagnosis of symptoms and signs”. Common clinical conditions from various systems are included. It is taken care for each topic to have a format of brief introduction with definition as applicable, enumeration of the differential diagnosis in text, box, table, and figure format as needed, explanation of differentiating each condition based on history, clinical features and investigations leading to particular diagnosis. Wherever possible algorithmic approach been adopted. Where it is essential, illustrations have been incorporated. Each chapter ends with important references for further reading. As the emphasis is on differential diagnosis, treatment aspects are not included as a conscious decision.