Dandruff explained in under 2 minutes. Dandruff Causes and Treatment

Normally skin cells continually replace themselves. They die and flake off. This process is invisible and renewal cycle requires around a month.
When this cell turnover is unusually rapid, dandruff develops.
Dead skin cells are shed in large, oily clumps, which appear as white or grayish flakes on the scalp, skin and clothes.
Dandruff is not due to poor hygiene. It worsens during winter.
Probably mechanism of Dandruff is, fungal infection, which is called Malassezia globose.
Normally; On the skin; we have sebaceous glands; which produces sebum.
Sebum lubricates, moistures and protects skin.
But this parasite fungus Malassezia globose releases lipase, and metabolizes sebum.
In a result we get oleic acid.
Oleic acid penetrates into the skin and causes inflammation of skin; disrupts skin metabolism and causes dandruff.
Dandruff is the mildest form of seborrheic dermatitis.
Treatment:
Most common treatment of dandruff is using shampoo which contains antifungal medication.
Such as: Ketoconazole; Bifonazole; Miconazole; Ciclopirox Olamine.
The form of These medications can be as shampoo ingredient, cream, gel or lotion.
Most common and effective is Ketoconazole.
Other treatment:
Coal tar causes the skin to shed dead cells from the top layer and slows skin cell growth.
Essential oils, such as tea tree oil can be effective in the treatment of dandruff.
By Horoporo - Own work, CC BY-SA 3.0, commons.wikimedia.org/w/index...
By AJC1 from UK - Malassezia globosa, CC BY-SA 2.0, commons.wikimedia.org/w/index...
By OpenStax College - Anatomy & Physiology, Connexions Web site. cnx.org/content/col11496/1.6/, Jun 19, 2013., CC BY 3.0, commons.wikimedia.org/w/index...
By Rusty.t.miller - Own work, CC BY 3.0, commons.wikimedia.org/w/index...