About one-third of women experience hair loss (alopecia) at some time in their lives; among postmenopausal women, as many as two-thirds suffer hair thinning or bald spots. Hair loss in women often has a greater impact than hair loss does on men w, because it's less socially acceptable for them. Alopecia can severely affect a woman's emotional well-being and quality of life.
The main type of hair loss in women is the same as it is men. It's called androgenetic alopecia, or female (or male) pattern hair loss. In men, hair loss usually begins above the temples, and the receding hairline eventually forms a characteristic "M" shape; hair at the top of the head also thins, often progressing to baldness. In women, androgenetic alopecia begins with gradual thinning at the part line, followed by increasing diffuse hair loss radiating from the top of the head. A woman's hairline rarely recedes, and women rarely become bald.
There are many potential causes of hair loss in women , including medical conditions, medications, and physical or emotional stress. If you notice unusual hair loss of any kind, it's important to see your primary care provider or a dermatologist, to determine the cause and appropriate treatment. You may also want to ask your clinician for a referral to a therapist or support group to address emotional difficulties. Hair loss in women can be frustrating, but recent years have seen an increase in resources for coping with the problem.
Clinicians use the Ludwig Classification to describe female pattern hair loss. Type I is minimal thinning that can be camouflaged with hair styling techniques. Type II is characterized by decreased volume and noticeable widening of the mid-line part. Type III describes diffuse thinning, with a see-through appearance on the top of the scalp.
What is androgenetic alopecia?
Almost every woman eventually develops some degree of female pattern hair loss. It can start any time after the onset of puberty, but women tend to first notice it around menopause, when hair loss typically increases. The risk rises with age, and it's higher for women with a history of hair loss on either side of the family.
As the name suggests, androgenetic alopecia involves the action of the hormones called androgens, which are essential for normal male sexual development and have other important functions in both sexes, including sex drive and regulation of hair growth. The condition may be inherited and involve several different genes. It can also result from an underlying endocrine condition, such as overproduction of androgen or an androgen-secreting tumor on the ovary, pituitary, or adrenal gland. In either case, the alopecia is likely related to increased androgen activity. But unlike androgenetic alopecia in men, in women the precise role of androgens is harder to determine. On the chance that an androgen-secreting tumor is involved, it's important to measure androgen levels in women with clear female pattern hair loss.
In either sex, hair loss from androgenetic alopecia occurs because of a genetically determined shortening of anagen, a hair's growing phase, and a lengthening of the time between the shedding of a hair and the start of a new anagen phase. (See "Life cycle of a hair.") That means it takes longer for hair to start growing back after it is shed in the course of the normal growth cycle. The hair follicle itself also changes, shrinking and producing a shorter, thinner hair shaft — a process called "follicular miniaturization." As a result, thicker, pigmented, longer-lived "terminal" hairs are replaced by shorter, thinner, non-pigmented hairs called "vellus."