The darkness on both sides of the cheeks may be a normal physiological phenomenon, or it may be caused by disease factors such as acanthosis nigricans and perifollicular keratosis, which need to be clarified after the cause of the targeted treatment, such as taking sunscreen measures, medical aesthetic treatments, medications, surgical treatments and so on. 1. Physiological factors: If the local skin sunscreen is not in place, long-term exposure to ultraviolet radiation may lead to local melanin deposition. It is recommended to evenly apply sunscreen and play sunshade when going out, etc. If necessary, you can also use photorejuvenation and other medical technology to remove melanin deposits on both sides of the cheeks. 2. Acanthosis nigricans: the cause of the disease is not clear, mainly characterized by excessive skin pigmentation and velvety thickening, and there are benign and malignant. Benign acanthosis nigricans can be improved by topical application of retinoic acid, salicylic acid and other keratolytic agents; malignant acanthosis nigricans patients with the presence of malignant tumors can be considered for surgical treatment. 3. Perifollicular keratosis: it is a chronic follicular keratosis skin disease, the cause of which is not yet clear, commonly found on the outer side of the upper arms and the extensor side of the thighs, and can also occur on the cheeks and buttocks, manifesting as normal skin color or reddish pimples with a chicken-skin-like appearance and a rough feel. No treatment is usually needed, and medications such as retinoic acid cream and tazarotene gel can be used to improve symptoms if necessary. The darkness on both sides of the cheeks may also be caused by other factors, it is recommended to consult a doctor in a timely manner in order to clarify the cause of the symptomatic treatment, to avoid private medication, so as not to delay the condition.