The possibility of seborrheic dermatitis is very high when you have extra oil on your face and head. Seborrheic dermatitis is a relatively common inflammatory skin disease in clinical practice. The cause of the disease is still unclear and is considered to be related to fungal infection, impaired skin barrier function, abnormal sebaceous gland secretion, and individual differences. It is also clinically found that the disease is directly related to patients’ high mental stress, irregular diet, smoking, drinking, staying up late, and liking to eat spicy and irritating foods. Seborrheic dermatitis occurs in areas where the sebaceous glands secrete a lot, such as the head, face, chest, and back, and there is usually varying degrees of itching. It can be recurrent and lingering for years. The most common areas are usually the scalp and face. Some people will have flaking and others will have a sticky, oily crust on their scalp with hair loss.