ALOPECIA ... DOES SOMETIMES ONLY A HAIR!

Throughout the life of a hair grow, some die and fall, while others are born or are in a growth phase. Among the 70,000 to 150,000 hair that adorn our head - or 200 to 300 hair per cm ² - 20 to 100 are in daily freefall! However, if this loss is called normal, it should start to worry when a handful of hair trap mouth of the shower, the pillow or invades the brush ... But why do we lose our hair ?

A bulb growth

The hair follicle is the envelope that fits the root, to 4 mm below the scalp . It is here that built the hair . Each follicle is composed of different elements, all vital to the production of keratin: the papilla, in which the blood reaches the matrix, which generates the keratin cells and transforms them into hair(keratinization) and epithelial ducts, which serve guardian of the hair shaft. Each hair follicle is programmed to push the hair permanently and to renew it once it reaches the end of the cycle. Above the follicle is the sebaceous gland attached that produces sebum.

Sebum, a poison?

Sebum secretion is dependent on androgens (hormones, adrenal and genital).Fat produced by the sebaceous gland, sebum normally lubricate the hair and wrap a protective microfilm, which is essential to its proper shape. However, under hormonal influence, the secretion of sebum, which can become excessive clogs the hair follicle, the precise place where are the reproductive cells of hair .This infiltration produces toxins that collect around the roots and disturb the blood circulation. Asphyxiated, roots then produce hair lower. This surplus production is one of the causes of androgenetic alopecia.

The growth cycle

Our hair is constantly renewed: their life cycle is on average 3 years in men, 5.7 years in women. During this period, each hair grows continuously. When he dies, he is immediately replaced by another. The dead hair will fall two to four months later, the time that the new growth finally ousted from its follicle. This growth cycle is defined in 4 stages.

Scenario 4 stroke

The growth phase called anagen: root fills the hair follicle to its base, the hair will grow for 2-7 years, depending on gender and individuals. The regression phase called catagen: 15 to 20 days. The root goes back to the skin, it loses some volume and activity abruptly stops. The hair stops growing and dies. But it will wait another 2 to 4 months before leaving. The expulsion phase called telogen: a young root takes place and is poised to displace the previous one.And finally the fall: the new growth reaches the surface of the scalp and the old hair falls out by itself. Fortunately, the follicles of hair do not all the same way. This explains a natural loss of about thirty hairs per day.