Dark spots on the face are mainly caused by melanin deposition, which may be caused by non-disease reasons such as ultraviolet radiation and living habits, or may be related to disease reasons such as acanthosis nigricans. 1. Non-disease causes: frequent working or laboring under the sun and too much time in the sun will lead to the appearance of dark spots on the face; frequent use of cosmetics containing excessive chemical pigments or mineral oil will lead to the appearance of dark spots on the face. 2. Disease reasons: skin diseases such as acanthosis nigricans can lead to the formation of dark spots on the face; diseases such as Addison’s disease, diabetes, hemochromatosis, hyperpigmentation intestinal polyp syndrome, endocrine disorders can also cause dark spots on the face. There are many reasons for dark spots on the face, only the common or important reasons are listed above. If patients find that they have dark spots on the face, it is recommended that they go to the dermatology department of regular hospitals for consultation and relevant examination according to the doctor’s suggestion to look for the corresponding causes of the disease and actively carry out the treatment.