Anemia is one of the most frequently encountered hematological disorders in internal medicine practice. However, this frequency does not reflect simplicity; rather, it highlights the diversity of underlying causes and the complexity of its clinical management. In daily clinical routines, the diagnosis of anemia may initially appear to be a mere laboratory finding, yet it actually marks the beginning of a process that requires multidisciplinary reasoning, clinical insight, and a systematic approach. 

This book has been prepared to present up-to-date information on anemia in a format that can be directly utilized by internal medicine specialists and residents during their clinical decision-making processes. It covers a wide spectrum—from basic hematologic mechanisms to differential diagnoses of complex conditions such as anemia of chronic disease, nutritional deficiencies, hemolytic processes, and bone marrow failure syndromes. Each chapter is supported by evidence-based data from the international literature and enriched with clinical experience. 

The purpose of this work is not only to provide theoretical knowledge but also to remind the reader that every anemia has its own “story,” and that 
behind every laboratory result lies an underlying pathophysiological process. The case examples, diagnostic algorithms, and laboratory interpretations included in this book are designed to be directly applicable in clinical practice. 

I would like to express my gratitude to all contributing authors, the editorial board, and my colleagues who devoted their time and effort to the preparation of this book. I hope this work will serve as a guide in the diagnosis and treatment processes of internal medicine, as an educational resource for residents, and as a reference book for specialists. 

Hatice Aktaş, MD