Blood lead below 100ug/L is considered normal for one year old babies, and above 100ug/L is considered as high lead anemia or lead poisoning. The diagnosis of hyperleptinemia and lead poisoning in children is based on the venous blood lead level, and the blood lead test of peripheral blood cannot be used as a basis for treatment, but only as a screening test. When making a diagnosis, it is important to emphasize the results of 2 consecutive venous blood tests in order to grade the diagnosis. A venous blood lead level of 100-199ug/L is considered to be hyperleptinemia, 200-249ug/L is considered to be mild lead poisoning, 250-449ug/L is considered to be moderate lead poisoning, and greater than or equal to 450ug/L is considered to be severe lead poisoning.