|
Should
I be concerned about the numbers of hairs I shed
In the keratin.com forums there are numerous messages about hair
shedding and how many hairs people lose each day. The number of
shed hairs scares people, but actually this is not necessarily the
cause of telogen effluvium. Some people can have very low levels
of hair shedding, but still have hair loss because the hairs shed
are not replaced by new hair growth. Conversely, some people have
very high shed rates, but no hair loss because the shed hair is
rapidly replaced by new hair. The frequently quoted average normal
shed rate is 100 hairs a day, but it is quite possible for normal
fully haired people to lose as many as 200 scalp hairs a day or
as few as 20.
The hair shedding rate can be affected by several factors. Women
may see rhythmic shedding rate changes as a consequence of their
hormone cycle. Hair shedding increases for both men and women during
late summer and early autumn as we grow our "winter coats"
and shedding is reduced in early summer. Shedding also increases
on days when hair is washed but decreases on the day immediately
after washing. This is because the physical manipulation of the
hair during washing encourages telogen hairs to come out and because
the hairs fell out during washing, there are fewer hairs to fall
out the day after. Beacuse the normal rate of hair shedding can
be so variable, and affected by several factors, defining an abnormal
rate of hair shedding is difficult.
Telogen effluvium has less to do with the rate of hair shedding
and more to do with hair follicles having a lag phase in the growth
cycle. They are entering a telogen resting state as normal, but
they are probably staying in that state for longer than they should.
More hair follicles in telogen means less hair growth and the result
is a gradual diffuse thinning of scalp hair. When diagnosing hair
loss, dermatologists place less emphasis on the rate of hair shedding,
but rather how much hair is left on the scalp. Dermatologists may
even use scalp biopsies to guage the percentage of hair follicles
in telogen. Fully haired peole may have between 10% and 20% of hair
follicles in a telogen state. People with telogen effluvium may
see that figure rise to 40% and occasionally even higher.
We each have about 100,000 scalp hairs (it ranges between 80,000
and 150,000). If you lost 500 hairs a day and there was no replacement
hair growth you would be entirely bald in 200 days. While extensive
baldness is possible with anagen effluvium as due to chemotherapy,
extensive hair loss is a rare event with telogen effluvium. This
shows that for most individuals with telogen effluvium some hair
regrowth and replacement of shed hairs probably occurs, although
not as fast as you might wish.
|
