This book is intended for use by interns, junior residents, first year medicine PG residents and non Medicine PGs/SRs as a comprehensive guide for their OPDs and to help clear doubts related to management and approach to common diseases. This book helps to understand the practical aspects of treating the most commonly seen, simple diseases which can and should ideally be treated by any MBBS graduate at the primary healthcare level. We all know what the biggest flaw in our medical education is: Immediately after MBBS, we know the theory of everything but the practical aspect is largely ignored (both by the system as well as the students who are keen on mugging up facts for the post-graduate entrances). Students know the pathogenesis and genetics of the rarest of the rare diseases but lack confidence in treating and approaching common diseases like diarrhoea, hypertension, hypothyroidism etc. This book gives an idea about basic treatment protocol to be followed as per standard guidelines and more importantly, tells when to refer to a specialist. Red flag signs when OPD treatment should not be continued at the primary care level have been mentioned wherever appropriate. The idea of this book is to give basic and comprehensive step–wise approach to common symptoms and diseases thus enabling all MBBS graduates to be able to manage the OPDs and medicine–related issues in their specialities. Hopefully, this book will also prove as a life saver for many interns, Junior residents posted in heavy OPDs, since the simple step–wise approach given in this book will help to take quick initial decisions regarding next investigation, treatment plan and when to refer. We sincerely hope that this book will help you in writing a prescription that is precise as well as prudent.