The total number of red blood cells results from a balance between the formation and degradation or loss of red blood cells. Anemia is thus the result of one or more of the three basic mechanisms (s classification of anemias for causes.):
As anemia is a reduction in the number of erythrocytes, the hematocrit or the hemoglobin value is referred to. The total number of red blood cells results from a balance between the formation and degradation or loss of red blood cells. Anemia is thus the result of one or more of the three basic mechanisms (s classification of anemias for causes.): Blood loss Insufficient erythropoiesis Excessive hemolysis (red blood cell resolution) Classification of anemias for causes mechanism Examples blood loss acute gastrointestinal bleeding injuries birth Surgical procedures Chronic Blas entumoren cancer or polyps in the gastrointestinal tract Heavy menstrual bleeding kidney tumors ulcers in the stomach or small intestine Insufficient erythropoiesis * microcytic iron deficiency iron transport disruption iron utilization disorder iron recycling disorder thalassemia (classified under “Excessive hemolysis by intraerythrocytic disorders”) normochromic normocytic Aplastic anemia hypo proliferation In kidney disease In endocrine disorder (thyroid, pituitary ) When protein deficiency myelodysplasia Myelophthise Macrocytic copper deficiency folic acid deficiency, vitamin B12 deficiency, vitamin C deficiency Excessive hemolysis by extraerythrozytäre disorders hyperactivity of the reticulo-endothelial system with splenomegaly hypersplenism Immunological disorders autoimmune hemolytic anemia hemolysis by cold antibody (paroxysmal cold hemoglobinuria) hemolysis by heat antibody Isoimmun- (Isoagglutinin-) hemolysis Mechanical injury infection Excessive hemolysis injury by intraerythrocytic disorders membrane alterations acquired hypophosphatemia paroxysmal nocturnal hemoglobinuria stomatocytosis membrane alterations, congenital hereditary elliptocytosis hereditary spherocytosis metabolic disorders (congenital enzyme deficiencies) disorders of the Embden-Meyerhof cycle glucose-6-phosphate dehydrogenase deficiency hemoglobinopathies Hemoglobin C disease hemoglobin E disease hemoglobin S-C disease hemoglobin-S-?-thalassemia sickle cell anemia (hemoglobin S) thalassemias (?, ?-? and ?) * Classified according erythrocyte indices. Blood loss can be acute or chronic. Anemia does not develop spontaneously, but only a few hours after acute blood loss when interstitial fluid diffuses into the vascular system and the remaining amount erythrocytes diluted. Nevertheless, it may within the first hour to an increase in polymorphonuclear granulocytes, platelets and – in severe bleeding – immature leukocytes and Normoblasts come. A chronic blood loss leading to anemia only if it runs faster than new production. More often, however, it comes at an increased erythropoiesis to depletion of iron stores in the body (see Fig. Iron deficiency anemia). Decreased erythropoiesis (s. Decreased erythropoiesis) has many reasons. A complete standstill of erythropoiesis resulting in a drop of erythrocytes of about 7-10% / week (1% / day). In a disturbed erythropoiesis occurs, even if this will not cause any decrease in red blood cell count, shape changes of erythrocytes size. Excessive hemolysis (s. Hemolytic anemia overview) can be caused by intraerythrocytic changes as well as by external factors such. B. by antibodies on their surface, which lead to premature breakdown of red blood cells. In splenomegaly, there is an increased sequestration and accelerated in comparison to the normal case Degradation of erythrocytes. Some forms of hemolysis lead to both deformation and destruction of red blood cells. When an excessive hemolysis may be the case only to the decrease of erythrocyte production when iron or other necessary components are reduced.