Dandruff is loose dead skin cells falling from your scalp. This can happen at any age. It has nothing to do with bad hair care. Even if you wash your hair often, you can still have dandruff. Dandruff that falls to the shoulders can be a source of real embarrassment. There are several possible causes of dandruff: stress, bad nutrition, lack of rest, frequent use of gels and hair sprays, excessive use of hot curling irons, etc.