Dandruff is a visible sign of scalp imbalance. It appears that when the natural cycle of cell renewal accelerates, corneocytes (cells of the stratum corneum) shed in larger, more noticeable clusters. This process is closely linked to microbial activity, sebum levels and individual scalp sensitivity.
Yeasts of the genus Malassezia, particularly Malassezia globosa and Malassezia restricta, are naturally present on the scalp of most individuals and usually exist in a balanced state. These species are lipid-dependent, meaning that the higher the sebum level on the surface, the more favourable their environment becomes.
When sebum production increases, this environment stimulates their metabolic activity. Under such conditions, Malassezia shifts into a more active phase, intensifying the enzymatic breakdown of sebum as a source of nourishment. As a result, free fatty acids — including oleic acid — are formed. Oleic acid alters the organisation of intercellular lipids within the stratum corneum, weakening the barrier’s structural integrity. The scalp becomes more reactive, and sensations such as itching or visible redness may develop.
In response, the scalp shifts into an accelerated renewal mode. Cells begin to divide more rapidly than usual, as if attempting to restore the surface. However, due to this shortened cycle, cells do not fully mature or separate individually. Instead, they cluster together and shed in larger flakes.
This is how dandruff develops. With persistent inflammation, the condition may progress to seborrhoeic dermatitis.