What is the main cause of a severe type of dandruff?

The main cause of a severe type of dandruff is a fungal infection, specifically from a yeast-like fungus known as Malassezia. This organism naturally resides on the scalp, but in some individuals, it can become overactive, leading to an increase in skin cell turnover. This rapid turnover produces an accumulation of dead skin cells on the scalp, which manifests as flaking or dandruff.

In addition to the fungal activity, factors like oil production, stress, and certain skin conditions can exacerbate the dandruff problem, but the root cause remains the fungal infection. Treatment typically involves antifungal shampoos or topical treatments designed to reduce the population of Malassezia and alleviate symptoms.