Iron is a vital micronutrient required by the human body. It facilitates a wide variety of physiological processes such as DNA synthesis, electron transport, and oxygen transport. The human body requires a right amount of iron. Deficiency of iron leads to anemia, i.e., low number of Red Blood Cells (RBCs) in the blood. In this condition, the blood does not transport adequate amount of oxygen in the entire body. Iron is a part of hemoglobin protein that is essential for transporting oxygen from lungs to all parts of the body. Some conditions such as pregnancy, ulcers, heavy periods, inherited disorders, and a diet lacking iron may also lead to the development of anemia. Hemochromatosis is a condition wherein a body absorbs too much iron from the food, which is stored in organs like liver, heart and pancreas. This may lead to liver disease, heart problems, and diabetes. This book outlines the role of iron in human diseases in detail. It will prove to be immensely beneficial to medical professionals and students involved in this area at various levels.