How much is the index of severe anaemia

If the hemoglobin concentration is lower than normal and greater than 90g/L, it is mild anemia. If the hemoglobin concentration is between 60 and 90g/L, it is moderate anemia. If the hemoglobin concentration is between 30 and 59g/L, it is severe anemia. If the hemoglobin concentration is lower than 30g/L, it is very dangerous and needs timely treatment.