For human beings, iron is an important trace element. It is required for various bodily processes such as cell growth and division, oxygen transport, various catalytic reactions, and oxidative metabolism. Human body requires only a small amount of iron on a daily basis. It must be consumed in a strictly monitored manner because there is no mechanism for excreting excess iron out of the body. Erythropoiesis, i.e., the production of new blood cells, takes place in the bone marrow, which is the major consumer of iron. The reticuloendothelial system helps in recycling iron by erythrocyte phagocytosis. Various proteins are involved in iron metabolism. For instance, hepcidin is a liver-derived peptide hormone that works as a major regulator of iron metabolism. This book explores all the important aspects of the physiology and pathophysiology of iron in the present day scenario. It is a valuable compilation of topics, ranging from the basic to the most complex advancements. Those in search of information to further their knowledge will be greatly assisted by this book.