Anemia is a condition characterized by a reduced blood hemoglobin level and / or a reduced number of erythrocytes. Erythrocytes are red blood cells produced in the bone marrow, and after matured they circulate in the blood. The main role of erythrocytes in the body is the transmission of oxygen to all organs. Hemoglobin is a protein that has the role of binding and transporting oxygen to distant organs, of which the brain, heart and muscles are particularly important.