What causes yellow skin?

The normal skin color of the body is relatively stable, if a woman's skin suddenly turns yellow, first of all, it may be staying up late, not resting well, and lack of necessary nutrients, etc. to slow down the metabolic rate; secondly, some drugs taken for a long time will also cause yellow skin, such as furazolidone; some diseases will also cause yellow skin, such as severe liver disease and so on.