The jaundice value of 21mg/dL in a newborn 4 days after birth is considered to be pathologic jaundice, which needs to be treated promptly.
The jaundice value is less than 12.9mg/dL for full-term newborns and less than 15mg/dL for preterm newborns, and the current jaundice value is 21mg/dL, which means that the jaundice value is relatively high and has reached the range of pathological jaundice, which needs to be treated in time in the hospital, or else it will lead to severe after-effects.
Newborns with pathological jaundice generally need to take blue light irradiation treatment, which can promote the subsidence of jaundice, and some newborns with severe jaundice may need to take blood transfusion treatment. Some newborns with severe jaundice may require blood exchange. Moreover, blood tests are often needed to clearly diagnose the cause of jaundice.
Newborns with jaundice of 21mg/dL are often more serious and should be seen promptly to avoid delay in treatment.