The production of hair is not continuous but cyclic. The growth phase (Anagen) is succeeded through a transitional phase of regression (Catagen), by the rest phase (Telogen), and the cycle is preserved.During the relatively long Anagen phase (lasts for 1,000 days, i.e. 2-5 years), the matrix cells divide, become keratinized and hair is produced. The Catagen phase lasts for about 2-3 weeks and is practically unimportant. During the Telogen phase, that lasts for several months,the cell division stops, hair growth ceases, and the attachment of the hair to the base of the follicle becomes progressively weaker. Finally, as a result of ordinary traction, whether that be from combing, from washing, its own weight, or a push by a new, growing hair, the old hair is eventually shed and discarded.