Iron deficiency anemia is a common benign anemia in clinical practice and can be cured in most patients after treatment with iron supplements. In general, the indicators of iron deficiency anemia include two conditions, including indicators of anemia and indicators of iron deficiency. For the indicators of anemia, in general, iron deficiency anemia is a small cell hypochromic anemia with hemoglobin generally below 120 g/L in men, below 110 g/L in women, below 100 g/L in pregnant women, average red blood cell volume less than 80 fL, average red blood cell hemoglobin concentration less than 32%, and average red blood cell hemoglobin content less than 27 pg. In addition, there is Evidence of iron deficiency, such as serum ferritin less than 12ug/L; bone marrow iron staining showing disappearance of small stainable iron grains in the bone marrow and less than 15% of iron-granulated young red blood cells; decreased serum iron and significantly higher total iron binding capacity.