Anemia of chronic disease occurs in patients with infectious, autoimmune, kidney diseases, neoplasia, inflammatory bowel disease, obesity, diabetes mellitus, congestive heart failure, and chronic lung disease. This variant of anemia is characterized primarily by impaired iron homeostasis, the suppressive effect of pro-inflammatory cytokines on erythropoiesis, and changes in the erythrocyte membrane that worsen their survival. Anemia of chronic disease is micro- or normocytic anemia with low levels of reticulocytes. In anemia of chronic disease, serum iron and transferrin levels are usually reduced or normal, and serum ferritin levels are within reference values or elevated. The article provides a review of studies on epidemiology, including age aspects, provides information on the etiology and prognosis in patients with anemia of chronic diseases. The issues of the history of anemia of chronic diseases and its place in the structure of all anemias are also covered. Anemia of inflammation is recognized as a widespread pathology; it occupies 40% in the structure of all anemias. It is important to note that anemia of chronic diseases, while accompanying a number of dangerous diseases, actually serves as a natural defense mechanism. This is due to the occurrence of iron starvation for microorganisms, since inflammatory reactions increase the synthesis of iron proteins, which quickly extract extracellular and unbound iron. This mechanism allows a person to destroy the infection in time with the help of innate immunity. The article reveals the pathogenetic aspects of anemia of inflammation development and data on the role of iron in the functioning of macro- and microorganisms. Particular attention is paid to the differential diagnosis of anemia of chronic diseases and iron deficiency anemia, key diagnostic hematological markers of anemia, iron metabolism, inflammation and erythropoiesis are given. The pros and cons of therapy options, as well as possible new pathogenetic methods for the treatment of anemia of chronic diseases, are described.