What is the main cause of dandruff?

Dandruff is primarily caused by an overgrowth of a type of yeast known as Malassezia. This organism is naturally found on the scalp of most people, but in some individuals, it can become imbalanced and proliferate excessively. This overgrowth disrupts the normal functioning of the scalp, leading to increased skin cell turnover and resulting in the flaking associated with dandruff.

While other factors, such as dry skin, excessive shampooing, or allergies to hair products, can contribute to scalp irritation or dryness, they are not the fundamental cause of dandruff itself. Dry skin could lead to mild flaking but is not specifically related to the yeast overgrowth that characterizes dandruff. Additionally, using too much shampoo might strip away natural oils but does not directly promote the growth of Malassezia. Allergies to hair products can lead to scalp conditions but are also separate from the yeast-related cause. Understanding that Malassezia overgrowth is the primary cause helps in effectively treating and managing dandruff, often through the use of antifungal shampoos that target this specific issue.