What is dandruff primarily characterized by?

Dandruff is primarily characterized by dry, flaky skin on the scalp. This condition occurs when the scalp's skin cells shed more rapidly than normal, leading to visible flakes that may be white or yellow in appearance. These flakes often accompany itching and irritation, making them a common concern. The underlying causes can vary, from dry skin to other dermatological conditions, but the hallmark sign remains the flakes themselves.

In contrast, other options describe conditions not related to dandruff. An oily scalp could be associated with different scalp issues like seborrheic dermatitis, while excessive hair growth or loss of hair are conditions that do not define dandruff. Thus, the defining characteristic of dandruff is indeed the presence of dry, flaky skin on the scalp.