A little dandruff is normal in a normal population with the shedding of the cuticle, but if there is a large increase in dandruff and increased oil production is a possibility of disease. The main causes are: first, seborrheic dermatitis, caused by increased and abnormal sebum metabolism, mainly manifested as the scalp produces red spots, scales, and increased oil production. Second, fungal infections are considered, also known clinically as ringworm of the head, and patients can also be accompanied by other fungal infections such as ringworm of the feet and ringworm of the femur. It is recommended to avoid spicy, oily and sweet foods, sleep, stay up as late as possible, reduce smoking and alcohol consumption, and use topical shampoo to wash the hair.