Situation more than dandruff, its flaking since long period of time. large chunks of dandruff at different parts of scalp. Increases and decreases with time but never gone. It doesn't goes with oiling or shampooying. My scalp is draught dry, even oiling seems like dry after few minutes. What this could be any why? Pls suggest what can be done naturally or medically? is it external thing or related to internal functioning.?