Heel blood is used to screen for inborn inherited metabolic diseases. Different diseases will have different manifestations, and most of them will show symptoms such as mental retardation, dull expression, excitability, drowsiness, depression, accompanied by lightening of skin and hair pigmentation, dryness of the skin, and a peculiar odor in the urine and sweat, abdominal distension, open-mouthed salivation, puffy eyes, and lack of weight gain. If you are found to be unqualified, you must go to the hospital in time, because genetic metabolic diseases usually do not leave sequelae after early dietary improvement and medication, and the younger the age at which treatment is started, the better the results.