Overview: Blue light exposure is the simplest and easiest way to treat neonatal hyperbilirubinemia and is quite safe. Although there are side effects, they are generally not dangerous and do not leave sequelae. The side effects of blue light therapy for newborns include the following. 1, fever: phototherapy when the entire newborn exposed to blue light, or visible light below will cause an increase in unmanifest water loss will cause fever, so special attention should be paid to hydration. 2, may cause DNA damage: Therefore, when taking blue light, special attention should be paid to protect the key parts, such as the testicles of male babies and female babies’ ovaries. 3, retinal damage: blue light also has some damage to the retina, can cause conjunctivitis, so newborns in the exposure to blue light, pay attention to protect the eyes with eye shields. 4, riboflavin damage: When irradiating blue light, it will cause the destruction of vitamin B2 (riboflavin), therefore, when irradiating blue light, pay attention to supplement vitamin B2. 5, diarrhea: Blue light irradiation will turn bilirubin from insoluble bilirubin into water-soluble bilirubin, which is excreted through the intestines and fluids. When discharged through the intestine, it will stimulate the gastrointestinal tract and cause diarrhea. At this time, pay attention to hydrate the infant. 6, bronze evidence: irradiation blue light, the baby’s skin will become bronze, but, after stopping phototherapy will be better. In summary: blue light is a very effective way to treat neonatal jaundice, but it has side effects in the treatment of clinicians will take into account these problems, the overall picture of blue light is still very safe and effective.