Hårscykeln

Hårscykeln, often translated as the hair cycle, refers to the natural, cyclical process of hair growth and shedding that occurs in mammals, including humans. This cycle is typically divided into three main phases: anagen, catagen, and telogen.

The anagen phase is the active growth phase. During this period, hair follicles are producing new hair shafts, which elongate and push through the skin. The duration of the anagen phase varies significantly depending on the location on the body and individual genetics, but for scalp hair, it can last for several years. This prolonged anagen phase is what allows scalp hair to grow to considerable lengths.

Following the anagen phase is the catagen phase, a short transitional period where hair growth ceases. The follicle shrinks and detaches from its blood supply, and the hair shaft becomes an inactive club hair. This phase typically lasts for a few weeks.

The final phase is the telogen phase, also known as the resting phase. During telogen, the club hair remains in the follicle, but no new growth occurs. This phase can last for several months. Eventually, the telogen hair is shed, either naturally or through external forces, and the follicle enters a new anagen phase, initiating the growth of a new hair.

The length and duration of each phase can be influenced by factors such as genetics, hormones, age, and overall health. Disruptions to this cycle can lead to conditions like alopecia, characterized by hair loss.