Anemia is a common clinical symptom caused by a variety of different reasons or diseases.When diagnosing anemia, the cause should be identified, and treatment should be carried out according to the different causes of anemia.The cytological classification of anemia includes macrocytic anemia, normocytic anemia, and microcytic hypochromic anemia.Microcytic hypochromic anemia refers to a condition where, when anemia occurs, the red blood cell volume is less than 80 femtoliters (fl), and the mean corpuscular hemoglobin concentration is less than 32%.Types of microcytic hypochromic anemia include iron - deficiency anemia, thalassemia, sideroblastic anemia, and chronic anemia.