can be due to many 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.
Eat a healthy diet. You can also take vit B6 and vit A and E which are good for hair and skin. Try medicated shampoos for dandruff
. There are a number of over-the-counter shampoos available that can help. The most effective ingredients -- antimicrobials -- to look for are zinc pyridinethione, selenium
If the symptoms persist please consult a trichologist for the confirmatory diagnosis and treatment.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.