Hiusvaihde

Hiusvaihde, a Finnish term translating to "hair gear" or "hair change," refers to the cyclical process of hair growth and shedding experienced by humans and many animals. This natural phenomenon is crucial for maintaining a healthy and functional coat or hair. The hair growth cycle consists of three main phases: anagen, catagen, and telogen.

The anagen phase is the active growth period, where hair follicles produce new hair shafts. The duration of this phase varies significantly depending on the location on the body and individual genetics, determining the maximum length of the hair. For scalp hair, anagen can last for several years.

Following anagen is the catagen phase, a transitional period where hair growth stops. The follicle begins to shrink and detach from its blood supply. This phase is relatively short, typically lasting a few weeks.

The final phase is telogen, the resting period. During telogen, the hair remains in the follicle, but no active growth occurs. Eventually, a new anagen phase begins, pushing out the old telogen hair and starting the cycle anew. This shedding and regrowth is the observable "hiusvaihde." Factors such as age, hormones, nutrition, and stress can influence the length and efficiency of these phases, potentially leading to changes in hair density and thickness.