What is the phase of hair growth characterized by the breakdown and change of hair growth?

The phase of hair growth characterized by the breakdown and change of hair growth is known as catagen. During this phase, which is often referred to as the transitional phase, hair follicles prepare for the shedding of hair. It typically follows the anagen phase, where active growth occurs, and precedes the telogen phase, during which the hair is at rest.

In the catagen phase, the hair follicle shrinks and detaches from the dermal papilla, leading to the cessation of hair growth as it prepares for eventual shedding. This phase is crucial because it marks the transition from active growth to a resting stage, allowing the hair follicle to either regenerate new hair or prepare for the natural shedding of the old hair.

Understanding the catagen phase is essential for anyone studying the hair growth cycle in the field of cosmetology, as it provides insight into the natural processes of hair development, maintenance, and loss.