Possible causes of dull and yellowish skin include chloasma, internal diseases, bad habits, etc., which can be improved by medication, medical aesthetic treatment and life conditioning. 1. Melasma: Facial pigmentation diseases such as melasma will not only lead to different degrees of facial discoloration, but also lead to yellowing and dullness of the skin. Patients with mild symptoms can apply hydroquinone cream, tretinoin, azelaic acid cream, compound arbutin, vitamin C essence and other creams to help improve pigmentation and brighten skin color, while severe cases can also be treated by fruit acid skin resurfacing, picosecond laser treatment and other aesthetic methods. 2. Internal disease: if the patient has chronic liver disease, severe anemia and other internal diseases, there will also be skin dark yellow performance, such patients should pay attention to the primary internal disease treatment, so as to help improve the dark yellow, such as chronic liver disease through glutathione and other hepatoprotective drugs to improve liver function; patients with severe anemia can be taken through the use of ferrous sulfate and other drugs to help improve. 3. Unhealthy habits: often stay up late, long-term sleep deprivation, long-term smoking, do not pay attention to the sun and other bad habits may also lead to dull yellow skin, such patients should pay attention to improve the habits of work and rest, to ensure that adequate sleep; light diet, quit smoking and alcohol; go out and pay attention to strengthen the measures of sunscreen, pay attention to do a good job of hydration and moisturizing work after cleansing, you can use whitening and brightening efficacy of the skincare products, and so on. It should be noted that the above treatment should be carried out under the guidance of a physician, do not self-medication, in order to avoid the occurrence of adverse reactions.