Am I Experiencing Hair Loss?
Common signals include a general thinning of the hair all over the head and/or moderate loss of hair on the crown or hairline. This usually begins about age 30, becomes noticeable around age 40, and may be even more noticeable after menopause. Female hair loss is usually an overall thinning - two hairs where five used to be. Women may also experience a receding hairline, but this is rare. About 20 million American women have such hair loss. As in males, hair follicles simply shut down, with hormones playing some role in the process.
What Causes Hair Loss in Women?
While hair loss may begin as early as age 30, noticeable pattern baldness in women starts shortly after menopause. Before menopause, production of female hormone estrogen is high. This protects hair follicles from the small amount of testosterone women produce. During and after menopause, production of estrogen slows down or stops, leaving the enzyme 5-alpha reductase free to convert testosterone into dihydrotestosterone, or DHT. This causes hair follicles to shrink and produce thinner, poor-quality hair.
Does Age Affect Hair Loss?
In men and women who are genetically predisposed to baldness, certain hair follicles start to produce an enzyme called 5-alpha reductase. This enzyme converts testosterone into DHT. Hair is composed of keratin, a tough protein also found in fingernails and toenails. When hair follicles encounter high concentrations of DHT, cells at the base of the follicles which produce the keratin cannot operate at full capacity. They then produce a hair thinner in diameter than normal hair, called a vellus hair. It appears as thin peach fuzz on the scalp in balding area.
