You might not think so but your hair has a life cycle of its own, in fact, it has three. First is the Anagen, this cycle last two to six years and is when your hair is healthy and growing. The second cycle is called Categen it is when your hair starts to thin and your hair follicles start to shrink. This phase lasts for a few weeks. The third Cycle is called Tologen, which is when your hair falls out to make room for new hair follicles.