Dandruff can be due to internal or external causes
. Internal causes
include hormonal imbalance, poor health, poor hygiene, allergic hypersensitivity, lack of rest, emotional stress, excessive consumption of sugar, fat or starch and heredity predisposition.
External causes include excessive use of hair sprays and gels, improper use of hair-coloring products, cold weather and dry indoor heating, infrequent shampooing of the hair or inadequate rinsing of the scalp and hair.