The domestic standard for anemia is hemoglobin concentration <120g/L for men, <110g/L for non-pregnant women, and <100g/L for pregnant women, and the classification of anemia is based on the concentration of hemoglobin, which is as follows: 1. If the hemoglobin concentration is between 61g/L-90g/L, it is called moderate anemia; 3. If it is within the range of 31g/L-60g/L, it is severe anemia; 4. If the hemoglobin concentration is ≤30g/L, it is called very severe anemia.