What is the main cause of dandruff?

The main cause of dandruff is the overgrowth of a yeast-like fungus called Malassezia. This fungus is a naturally occurring microorganism that lives on the scalp and other areas of the skin. Under certain conditions, such as an imbalance in the scalp's natural oils, the Malassezia can multiply excessively. This overgrowth can lead to irritation of the scalp, seborrheic dermatitis, and the shedding of skin cells, which we recognize as dandruff.

In contrast, while an allergic reaction to hair products may cause scalp irritation and lead to flaking, it is not a primary cause of dandruff. The build-up of dirt and pollution might contribute to scalp health issues but does not directly cause the fungal overgrowth associated with dandruff. Similarly, although lack of proper hair washing techniques can exacerbate scalp conditions, it is not the root cause of dandruff itself; rather, it might lead to a worsening of an already existing condition predominantly caused by the Malassezia fungus.