Black patches on the arm may be caused by hyperpigmentation, coffee spot, nevus and other factors, which can be relieved by cooperating with doctors to choose medication, laser treatment, surgery and other ways. 1. Hyperpigmentation: most of them are post-inflammatory hyperpigmentation, which will not affect the patient’s health. If you feel that it affects the aesthetics, it can be treated with drugs such as hydroquinone cream and adapalene, which can play a role of epidermal cell renewal and exfoliation, and help to improve the patient’s symptoms. 2. Coffee spot: some of them are hereditary diseases, most of them don’t need special treatment, if you think it affects the aesthetics, you can cooperate with the doctor to choose Q laser, intense pulsed light and other ways of treatment. 3. Nevus: black patches on the arm can also be treated with laser therapy to improve the local appearance, but some patients may need multiple treatments to see the effect. For the plaques protruding from the skin surface, in the case of a large area, you can also cooperate with the doctor to choose the surgical way of excision treatment. After the black plaque on the arm, patients should be combined with their own situation, cooperate with the doctor for treatment. The above drugs and operations should be carried out under the guidance of a doctor.