Dandruff is a normal hair metabolism product that may increase in the following disease conditions. First, seborrheic dermatitis. In the case of high oil secretion, the scalp metabolism is high, which favors the growth of Malassezia and may lead to high secretion of dandruff. Second, fungal infection. For example, Trichophyton rubrum, Microsporum canis, etc. infect the scalp. Third, psoriasis, etc. Psoriasis can lead to abnormal cellular keratinization, manifesting as scaly erythematous plaques, which also occur on the scalp. If the symptoms are mild, the diagnosis may be missed because it is confined to the scalp. Therefore, when there is more dandruff, you can shampoo your hair with ketoconazole shampoo and skin nourishing shampoo 2-3 times a week. Take care not to stay up late and eat less spicy stimuli. If it does not heal repeatedly, it is recommended to consult a doctor to exclude psoriasis.