Long spots on cheeks may be caused by endocrine disorders or sun exposure, such as melasma, and may also be caused by heredity and sun exposure, such as freckles. 1. Melasma: Melasma is a yellowish-brown pigmentation on the face caused by endocrine dysfunction or sunlight irradiation. It is usually distributed symmetrically on the cheeks and commonly found in females, and the symptoms of melasma will be gradually serious with the growth of age, so the patients do not need to worry too much about it, and it will not do any damage to their own health. 2. Freckles: the cause of freckles is mainly hereditary, with the phenomenon of family aggregation. Too much exposure to sunlight or ultraviolet rays will aggravate the appearance of freckles, and can make the color of freckles become deeper, the number of freckles become more numerous, and the shape become bigger. There may be age spots, pregnancy spots, etc. The symptoms of freckles on the face alone cannot accurately determine the cause, but need to be combined with the characteristics of medical history and other examination results to make accurate judgment, and it is recommended to clarify the cause under the guidance of doctors.