Whether or not it is physiological jaundice is mainly determined by the jaundice index at the time of examination, and cannot be judged solely on the basis of where the jaundice occurs. Pathological jaundice may also occur without yellowing of the hands and feet, and physiological jaundice may also occur with yellowing of the hands and feet. Physiological jaundice is usually seen in newborn patients and is a disease caused by excessive accumulation of bilirubin after birth, usually manifesting as yellowing of the face, trunk, extremities, and the hearts of the hands and feet in newborns, but due to large individual differences, physiological jaundice in newborns may also occur early in life when the hands and feet are not yellow. The order of jaundice in newborns is usually head and neck first, followed by the trunk and then spreading to the distal end. When jaundice appears early in a newborn, only the head, neck, and trunk may appear yellow, before it radiates to the hands and feet, so the symptoms are not locally yellow. Symptoms of physiologic jaundice develop in newborns 1-2 days after birth and usually develop rapidly, and may be accompanied by elevated body temperature, low milk intake, and vomiting, and may begin to subside within 2 weeks, depending on the situation. However, if the jaundice lasts longer than 2 weeks, pathological jaundice may develop and should be seen by a hospital promptly. Pathological jaundice can lead to impaired mental development or death in newborns in severe cases, so early diagnosis can play an extremely important role. If jaundice occurs in adults, they should be checked for liver and biliary diseases, biliary stasis, and impaired bilirubin excretion. Patients with jaundice should avoid scratching due to itchy skin in daily life to avoid symptoms such as mucosal breakage or infection.