The diagnosis of iron deficiency anemia includes: 1. understanding symptoms and physical examination: patients often present with symptoms such as chest tightness, shortness of breath and weakness; 2. blood tests: including routine blood tests, serum ferritin, free iron and other tests. Serum ferritin is the gold standard for diagnosis. The normal value of hemoglobin is 110g/L, below 30g/L is very severe anemia, below 60g/L is severe anemia, 60g/L-90g/L is moderate anemia, and 90g/L-110g/L is mild anemia. The quality of life of severe patients can be improved through blood transfusion therapy, in addition to measures such as iron supplementation therapy and etiological treatment.