Hair Cycle

The growth of our hair is cyclic. It consists of a growing phase, a short transition phase, and a resting phase. The World Book Encyclopedia explains: "A hair stops growing during every resting phase, when it is known as a club hair. The club hair remains in the resting follicle until the next growing phase. During the growing phase, the club hair is shed as a new hair grows and pushes it out of the follicle." At any given time, while 85 to 90 percent of hairs are in the active phase, 10 to 15 percent will be in the resting phase and 1 percent in the transition phase.

How thick is hair? According to a survey, it can vary from 50 microns in some people to 100 microns in others. Hair becomes thinner as one ages. Just a few microns' difference may not seem significant. But please recall that there are 100,000 hairs. So just a slight thinning of individual hairs results in a big difference in the total volume.