Facts About Hair Loss
Hair grows in a cycle that is commonly represented by phases. The active or “anagen” phase is when the hair is actively growing. Mature hair is referred to as “terminal”. On the head, about 80% to 85% of hair is anagen at any given time, whereas on the body, only 20% to 25% of the hair is anagen at any given time. The diagram below shows the phases of hair growth.
Understanding Hair Growth
The cycle of hair growth can take anywhere from 2 to 7 years. This is why some people can grow theirs longer than others. If the hair grows for 7 years at a rate of 1cm per month (average) then the person whose hair grows for 7 years will be a lot longer than the person whose hair only grows for 2 years.
When a hair reaches the end of its lifespan, it will start to disengage from the hair follicle. This is called the “categen” stage. Over the next 6 to 8 weeks, the hair will fall out, the follicle will rest (“telogen” stage), and a new hair will start to grow. It is common for people to lose 50 to 100 hairs per day because of this transitioning of the hair. People will often attribute this to permanent or abnormal hair loss however it is important to remember that everybody experiences hair loss due to the hair growth cycle.