The hemoglobin test includes two parts, one is the hemoglobin concentration test and the other is the hemoglobin electrophoresis test. The hemoglobin concentration test includes a test to see if the hemoglobin concentration is decreased. If hemoglobin concentration decreases, it is common for various causes of anemia, such as iron deficiency anemia, aplastic anemia, megaloblastic anemia, hemolytic anemia, and blood loss anemia. Increased hemoglobin concentration is common in various myeloproliferative disorders, such as true erythropoietic disorders, primary thrombocytosis, etc. Chronic hypoxic diseases may also have high hemoglobin concentration due to increased erythropoietin concentration in the body. Hemoglobin electrophoresis is a test to detect the presence of abnormal structure of hemoglobin. If abnormalities are found in hemoglobin electrophoresis, they are often seen in patients with thalassemia, a genetic disorder caused by disorders of peptide chain synthesis of beads. An abnormal hemoglobin electrophoretic band is found during the hemoglobin test due to impaired protein peptide chain synthesis and is often suggestive for the diagnosis of thalassemia.