Anemia is a pathological condition that results from a decrease in the total number of red blood cells in the body, which does not provide adequate oxygen to tissues and organs. Typically, indicators of anemia include hemoglobin, red blood cell count, and hematocrit. An adult male is considered anemic if his hemoglobin is <120 g/L, his red blood cells are <4.5×10^12/L, and his hematocrit is <0.42. And the indicators of anemia in adult females are hemoglobin <110g/L, red blood cells <4.0×10^12/L, and hematocrit that is <0.37, which is considered as the condition of anemia. In addition to the above indicators, patients with anemia should also pay attention to the average red blood cell volume, the average red blood cell hemoglobin content and the average red blood cell hemoglobin concentration, through these 3 indicators can generally determine the type of anemia.