What are the four phases of the hair growth cycle?

The correct answer identifies the four phases of the hair growth cycle as anagen, catagen, telogen, and exogen.

In the anagen phase, hair actively grows; this is the longest phase and can last for several years. The speed of growth during this phase can vary from person to person.

The catagen phase follows, representing a transitional period where hair growth slows and the hair follicle shrinks. This phase lasts for a few weeks.

Next is the telogen phase, during which hair is at rest and the old hair is shed. This phase can last for several months.

Finally, the exogen phase is when the hair is shed completely, making way for new hair growth as the cycle restarts with another anagen phase.

The understanding of these phases is crucial for professionals in esthetics and hair care, as it helps in managing and treating various hair and scalp issues.