Dihydrotestosterone (DHT), a derivative of the male hormone testosterone, is the enemy of hair follicles on your head. Simply put, under certain conditions DHT wants those follicles dead. This simple action is at the root of many kinds of hair loss, so we'll address it first.
Androgenetic
alopecia, commonly called male or female pattern baldness, was only partially
understood until the last few decades. For many years, scientists thought that
androgenetic alopecia was caused by the predominance of the male sex hormone,
testosterone, which women also have in trace amounts under normal conditions.
While testosterone is at the core of the balding process, DHT is thought to be
the main culprit.
Testosterone
converts to DHT with the aid of the enzyme Type II 5-alpha reductase, which is
held in a hair follicle's oil glands. Scientists now believe that it's not the
amount of circulating testosterone that's the problem but the level of DHT binding
to receptors in scalp follicles. DHT shrinks hair follicles, making it
impossible for healthy hair to survive.
The
hormonal process of testosterone converting to DHT, which then harms hair
follicles, happens in both men and women. Under normal conditions, women have a
minute fraction of the level of testosterone that men have, but even a lower
level can cause DHT- triggered hair loss in women. And certainly when those
levels rise, DHT is even more of a problem. Those levels can rise and still be
within what doctors consider "normal" on a blood test, even though
they are high enough to cause a problem. The levels may not rise at all and
still be a problem if you have the kind of body chemistry that is overly
sensitive to even its regular levels of chemicals, including hormones.
Since
hormones operate in the healthiest manner when they are in a delicate balance,
the androgens, as male hormones are called, do not need to be raised to trigger
a problem. Their counterpart female hormones, when lowered, give an edge to
these androgens, such as DHT. Such an imbalance can also cause problems,
including hair loss.
Hormones
are cyclical. Testosterone levels in some men drop by 10 percent each decade
after thirty. Women's hormone levels decline as menopause approaches and drop
sharply during menopause and beyond. The cyclic nature of both our hair and
hormones is one reason hair loss can increase in the short term even when you
are experiencing a long-term slowdown of hair loss (and a long-term increase in
hair growth) while on a treatment that controls hair loss.
The
following are the most common causes of women’s hair loss:
Andogenetic
Alopecia
The
majority of women with androgenic alopecia have diffuse thinning on all areas
of the scalp. Men on the other hand, rarely have diffuse thinning but instead
have more distinct patterns of baldness. Some women may have a combination of
two pattern types. Androgenic alopecia in women is due to the action of
androgens, male hormones that are typically present in only small amounts.
Androgenic alopecia can be caused by a variety of factors tied to the actions
of hormones, including, ovarian cysts, the taking of high androgen index birth
control pills, pregnancy, and menopause. Just like in men the hormone DHT
appears to be at least partially to blame for the miniaturization of hair
follicles in women suffering with female pattern baldness. Heredity plays a
major factor in the disease.
Telogen
Effluvium
When
your body goes through something traumatic like child birth, malnutrition, a
severe infection, major surgery, or extreme stress, many of the 90 percent or
so of the hair in the anagen (growing) phase or catagen (resting) phase can
shift all at once into the shedding (telogen) phase. About 6 weeks to three
month after the stressful event is usually when the phenomenon called telogen
effluvium can begin. It is possible to lose handful of hair at time when in
full-blown telogen effluvium. For most who suffer with TE complete remission is
probable as long as severely stressful events can be avoided. For some women
however, telogen effluvium is a mysterious chronic disorder and can persist for
months or even years without any true understanding of any triggering factors
or stressors.
Anagen
Effluvium
Anagen
effluvium occurs after any insult to the hair follicle that impairs its mitotic
or metabolic activity. This hair loss is commonly associated with chemotherapy.
Since chemotherapy targets your body’s rapidly dividing cancer cells, your
body’s other rapidly dividing cells such as hair follicles in the growing
(anagen) phase, are also greatly affected. Soon after chemotherapy begins approximately
90 percent or more of the hairs can fall out while still in the anagen phase.
The
characteristic finding in anagen effluvium is the tapered fracture of the hair
shafts. The hair shaft narrows as a result of damage to the matrix. Eventually,
the shaft fractures at the site of narrowing and causes the loss of hair.
Traction
alopecia
This
condition is caused by localized trauma to the hair follicles from tight
hairstyles that pull at hair over time. If the condition is detected early
enough, the hair will regrow. Braiding, cornrows, tight ponytails, and
extensions are the most common styling causes.
