The hormone responsible for hair growth in women is testosterone. As a woman ages, her body naturally begins to produce more testosterone and less estrogen, creating an imbalance. This imbalance means that females can experience unwanted hair growth.
Hirsutism is a hormonal imbalance that causes women to grow hair in areas in which males typically do, such as the upper lip, the chest area, the thighs, the chin and the back area.
Causes for Hirsutism
The most common causes for hirsutism are polycystic ovary syndrome, menopause and idiopathic illness.
Polycystic Ovary Syndrome
With polycystic ovary syndrome (PCOS), the female will cease menses due to cyst formation on the ovaries, causing dips in estrogen production. The reduced production of the female hormones means that male hormones naturally produced in the body will build up and be more pronounced. The higher amounts of male hormones will stimulate hair follicles, and unwanted hair growth will occur.
While the mechanism is the same for menopause, the reasons are not. Menopause is a naturally occurring, age-related reduction in female hormones. Unlike PCOS, the female will cease menses due to the ovaries not releasing eggs to fertilize, rather than cysts on the ovaries. When the ovaries cease egg production, estrogen and progestin are reduced, causing testosterone to be the main hormone in production, which in turn results in hair growth.
Idiopathic (meaning an undefined cause) hirsutism occurs when no primary cause can be found. Causes for idiopathic hirsutism can be due to adrenal gland overproduction, pituitary gland overactivity, tumors on the adrenal or pituitary glands, other hormonal imbalances and even stimulation from certain prescription drugs.