Excessive sebum secretion can be stimulated by various factors, which can be external (pollution, temperature, stress) or internal (hormonal imbalance). These skin types not only produce more sebum but the sebum itself has a different quality of composition.

This disorder in the condition of the skin leads to hyperkeratinization of the corneal layer as the development of a self-defense mechanism and the development of bacteria that would not normally exist. Excessive sebum secretion in combination with thickening of the skin blocks the follicles in the skin, clogging the pores which can become pimples (pimples) or microcysts (whiteheads). This results in the spread of bacteria (Propionebacterium Acne, Propionebacterium epidermidis, Malassezia furfur) which leads to the appearance of acne and oily skin.