Itchy hair always scratching head may be caused by untimely cleaning, may also be seborrheic dermatitis, ringworm, contact dermatitis and other diseases. 1. not timely clean: if the patient does not wash his hair on time in daily life, it will lead to excessive secretion of oil from the scalp, which will lead to the phenomenon of itchy hair always scratching the head. 2. Seborrheic dermatitis: the etiology of seborrheic dermatitis is not yet clear, and it is mostly considered to be related to Malassezia colonization, increased lipids, impaired skin barrier function, immune response and individual susceptibility. Patients will appear erythema, itching, white dandruff and other symptoms, if the patient’s condition is serious, there will be erosion, odor and other symptoms. 3. Tinea capitis: caused by fungal infection of the scalp and hair, often manifested as erythema, scaling, alopecia, itching and other symptoms. 4. Contact dermatitis: an allergic or irritant reaction that occurs when the scalp comes into contact with certain sensitizing or irritating substances. Will also cause scalp itching, at the same time there are erythema, papules and other skin lesions performance. When patients have the symptom of itchy hair always scratching their head, if it is caused by inadequate cleaning, it does not need to be treated. If it is caused by a disease, patients should seek medical treatment in time and follow the doctor’s instructions.