Spots may be caused by melasma, freckles, seborrheic keratosis, facial brownish green spots and other diseases, which may be related to ultraviolet irradiation, heredity, skin aging and other factors. 1. Melasma: If exposed to ultraviolet rays for a long time, it may damage the skin barrier and increase the activity of melanin cells, thus causing melasma. Genetic susceptibility and changes in sex hormone levels may also induce the disease. 2. Freckles: Heredity is the main factor of freckles, if parents suffer from freckles, the chances of the next generation will be increased. Excessive sun exposure may also aggravate or induce the disease. 3. Seborrheic keratosis: It is mainly related to skin aging, as the skin gradually ages with the increase of age, spots may appear, and secondly, gene mutation and other reasons may also induce the disease. 4. Facial brownish-blue spots: also known as zygomatic brownish-blue nevus, occurring in young women aged 20-30 years old, clinically manifested as round, scattered and non-combined grayish-blue spots symmetrically distributed in bilateral zygomatic and temporal areas. As there are many reasons for the spots, it is recommended that patients go to regular hospitals for consultation and examination to clarify the causes.