The criteria for blood lead poisoning is that the level of elemental lead in the blood exceeds the normal value of blood lead level, when the blood lead is too high it will cause lead poisoning. Currently the most commonly used grading standards for lead poisoning are: 1.Grade I: <100ug/L. A range that is less harmful to the human body and causes insignificant lesions. 2. Grade II: 100-199ug/L. Lead levels that reach this range will affect nerve conduction speed and cognitive ability, and children may experience dizziness, irritability, inattention, and hyperactivity. 3. Grade III: 200-449ug/L. It can cause many kinds of micronutrient deficiencies, growth retardation, decreased immunity, uncoordinated movement, visual and hearing impairments, slow response, decreased IQ, anorexia, heterophagia, anemia, and abdominal pain; 4. Grade IV: 450-699ug/L. This range of lead poisoning will show personality changes, aggressive behavior, learning difficulties, abdominal colic, hypertension, cardiac arrhythmia and movement disorders; 5. Grade V: ≥700ug/L. Lead poisoning level has reached the highest level, which can lead to multiple organ damage, lead encephalopathy, paralysis, coma and even death. Lead poisoning can cause children’s physical discomfort, if the relevant symptoms, you need to go to the regular hospital in time for treatment to control the condition.