The cause of yellowing of the skin may be certain physiological factors, but also may be due to certain disease factors, such as liver disease and so on. 1. Physiological factors: If you eat carotene-rich foods for a long time, such as carrots, oranges, pumpkin, red palm oil, etc., can be caused by elevated levels of carotenoids in the blood, thus causing the skin to turn yellow. In addition, long-term late at night, tired, too much mental stress, etc., will affect the skin metabolism, circulation, but also prone to skin darkening, yellowing phenomenon. 2. Hepatobiliary diseases: such as chronic hepatitis, viral hepatitis, alcoholic hepatitis, jaundice, etc., these diseases will have liver function damage, which will cause liver cell destruction, liver transformation and excretion of bilirubin ability to decline, bilirubin with the blood to the skin, causing yellow skin and mucous membrane. It is recommended that if the patient excludes physiological factors, need to go to a regular hospital, follow the doctor’s instructions to clarify the cause of the disease, and actively treatment, to avoid delaying the condition.