Forehead spots may be caused by sun exposure, ageing or endocrine disorders. 1. Sun exposure: Since forehead is a high-exposure part, if patients are exposed to sunlight for a long time, their skin will be strongly irradiated by ultraviolet rays, which will play a self-protective function and produce a large amount of melanin to resist ultraviolet rays, and the pigmentation will be deposited on the forehead to form pigmentation spots. 2. Ageing: Older people will have age spots with degenerative skin changes, also called seborrheic keratosis, which is a kind of pigment deepening rash formed by skin aging, and the number gradually increases with age. 3. Endocrine disorders: irregular work and rest due to stressful life and work, as well as female pregnancy can cause endocrine disorders, which will increase the abnormal secretion of melanin, which will be deposited on the forehead and lead to spots. There are many reasons for spotting on forehead, it is recommended to consult a doctor in time to clarify the cause of the problem and carry out targeted treatment or therapy with the help of a doctor.