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.
The most common reasons that cause hair loss are a combination or stand alone causes like stress, poor nutrition, hormonal imbalances, scalp bacteria and genetic baldness.During the years medical researches show that nearly 95% in both genders suffer from hair loss because of the genetic pattern baldeness.Inherited, or pattern baldness, affects many more men than women. Those with inherited hair loss show signs of hair loss before age 40. About half of all men show signs of hair loss by age 50. Source:MedlinePlus Medical Encyclopedia
Some women ages 30 to 60 may notice a thinning of the hair that affects the entire scalp. The hair loss may be heavier at first, and then gradually slow or stop.Hair loss usually develops gradually. It may be patchy or all over (diffuse). People lose roughly 100 hairs from your head every day while the scalp contains about 100,000 hairs approximately.