Dandruff may be caused by physiological factors such as not paying attention to hygiene, or it may be caused by seborrheic dermatitis, tinea capitis and other diseases. 1. Physiological factors: If you don’t pay attention to cleaning the skin on your head or have poor hygiene habits, it may lead to the phenomenon of large dandruff. 2. Seborrheic dermatitis: its causes are mostly related to heredity, age, microbial infections and other factors, patients will have chaff-like flakes on the head, and some patients will have large dandruff symptoms. 3. Tinea capitis: its etiology may be related to dermatophytes invading the skin, clinical manifestations of alopecia areata, scaling and hair breakage and other symptoms, some patients will have large scales on the scalp. Causes of dandruff large chunks of more reasons, in the exclusion of physiological factors, it is recommended that patients seek medical examination to clarify the cause of the disease.