For anemia, it will likely to be interested in the levels of the red blood cells contained in blood (hematocrit), hemoglobin,  mean corpuscular volume. determine the size and shape of red blood cells; some of red blood cells might also be examined for unusual size, shape and color. serum ferritin; This protein helps store iron in the body, a low levels of ferritin usually indicates a low levels of stored iron. serum vitamin B12; low levels usually develop an anemia, vitamin B12 is needed to make red blood cells, which carry oxygen to all parts of human body. blood tests to detect rare causes; such as an immune attack on red blood cells, red blood cell fragility, and defects of enzymes, hemoglobin, and clotting. a bone marrow sample; when the cause is unclear, a bone marrow test is performed, most often, when some blood cell defect is suspected.Reticulocyte counts, and the "kinetic" approach to anemia, have become more common than in the past in the large medical centers of the United States and some other wealthy nations, in part because some automatic counters now have the capacity to include reticulocyte counts. A reticulocyte count is a quantitative measure of the bone marrows production of new red blood cells. The reticulocyte production index is a calculation of the ratio between the level of anemia and the extent to which the reticulocyte count has risen in response. If the degree of anemia is significant, even a "normal" reticulocyte count actually may reflect an inadequate response.
Myelodysplastic syndrome
anemia of chronic inflammation
Leukoerythroblastic anemia is caused by space-occupying lesions in the bone marrow that prevent normal production of blood cells. Increased destruction
Anemias of increased red blood cell destruction are generally classified as hemolytic anemias. These types generally feature jaundice, and elevated levels of lactate dehydrogenase. Intrinsic (intracorpuscular) abnormalities cause premature destruction. All of these, except paroxysmal nocturnal hemoglobinuria, are hereditary genetic disorders.Hereditary spherocytosis is a hereditary defect that results in defects in the RBC cell membrane, causing the erythrocytes to be sequestered and destroyed by the spleen. Hereditary elliptocytosis is another defect in membrane skeleton proteins. Abetalipoproteinemia, causing defects in membrane lipids
Enzyme deficiencies
Pyruvate kinase and hexokinase deficiencies, causing defect glycolysis
Glucose-6-phosphate dehydrogenase deficiency and glutathione synthetase deficiency, causing increased oxidative stress
Hemoglobinopathies
Sickle cell anemia
Hemoglobinopathies causing unstable hemoglobins
Paroxysmal nocturnal hemoglobinuria
Extrinsic (extracorpuscular) abnormalities
Antibody-mediated
Warm autoimmune hemolytic anemia is caused by autoimmune attack against red blood cells, primarily by IgG. It is the most common of the autoimmune hemolytic diseases. It can be idiopathic, that is, without any known cause, drug-associated or secondary to another disease such as systemic lupus erythematosus, or a malignancy, such as chronic lymphocytic leukemia. Cold agglutinin hemolytic anemia is primarily mediated by IgM. It can be idiopathic or result from an underlying condition.