Dandruff/ any form of scalp dryness on the head can become embarrassing when constant flakiness becomes the order of the day, it won't be a good sight to have patches of whitish oily dead skin all over the head or on clothing and this is a common quality of dry scalp and dandruff.
Usually caused by lifestyle habits amongst other things not tending to the hair as should be especially is a major cause of dry skin and dandruff. Smoking, soda and a poor diet also worsen this common issue.
Taking time to massage in hair products making sure the scalp is well moisturized, drinking enough water, eating enough greens/vegetables and more also works to keep the scalp in great condition so also does home remedies.
This homemade lemon mask in super easy steps work to keep dry scalp in check.
(Sometimes, this could be a serious skin issue in which case expert opinion is best sought).