The causes of coffee spots are mostly considered to be physiological factors, and there may be pathological factors, such as neurofibromatosis, some rare diseases, etc. The specific analysis is as follows: 1. Physiological factors: some patients with cafe-au-lait spots can be born with cafe-au-lait spots on the skin of the body, the etiology of which is not yet clear, and it may be related to embryonic development, gene mutation, etc. If there is no other systemic discomforts, it usually does not affect the health, and there is no need for treatment. 2.Pathologic factors (1) Neurofibromatosis: It is a chromosomal dominant disease, and people with family genetic history are more likely to suffer from this disease. It can be manifested as coffee spots on the skin, accompanied by subcutaneous soft tissue masses, which can be distributed on the trunk, limbs and face, with smooth surface and intact skin, and the affected tissues can be yellowish-brown or pinkish-red. (2) Certain rare diseases: Albright syndrome, for example, is a disease in which the normal bone tissue mesenchyme is replaced by hyperplastic fibrous tissue, accompanied by endocrine disorders and combined with skin pigmentation. In the early stage of the disease, the symptoms can be manifested as café-au-lait spots, accompanied by shortness of body and hormone secretion abnormality, etc. The cause of the disease is unknown, and the younger the age of onset, the more serious the symptoms are. Patients with café-au-lait spots should go to the dermatology department of regular hospitals in time for dermoscopy, which can observe the increase of melanin in the basal layer, and at the same time, combined with the other clinical manifestations of the patients, a clear diagnosis will be made and targeted treatment will be given.