Hair Loss in Men and Women
Medical Author: Alan Rockoff, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
What are causes of hair loss?
There are many causes of scalp hair loss. This article will cover the common
ones.
In general, most hair loss is not associated with systemic or internal
disease, nor is poor diet a frequent factor. Thyroid disease can cause hair
loss, but thyroid tests on people who have ordinary hair loss are usually
normal. Although many medications list "hair loss" among their potential
side effects, drugs are also not overall common causes of thinning or lost hair.
On the other hand, with cancer treatments and immune suppression medications,
hair loss is not uncommon.
One useful way to classify hair loss is by whether
the loss is localized and patchy, or whether it affects large areas or the whole
scalp.
Patchy hair loss
Some conditions produce small areas of hair loss, while others affect large
areas of the scalp. Common causes of patchy hair loss are:
Alopecia areata
A common condition,
alopecia areata usually starts as a single, quarter-sized circle of perfectly
smooth baldness. Alopecia patches usually regrow in three to six months without
treatment. Sometimes, hair grows back in white. In another variant, alopecia can
produce two or three bald patches. When these grow back, they may be replaced by
others. The most extensive form is called alopecia totalis, in which the entire
scalp goes bald. It's important to emphasize that patients who have localized
hair loss generally don't go on to lose hair all over the scalp. Alopecia can
affect hair on other parts of the body too-- for example, the beard.
Alopecia areata is considered an autoimmune condition, in which the body attacks itself
(in this case its own hair follicles). Most alopecia patients, however, do not
have systemic problems and need no medical tests. Alopecia is also often blamed
on "stress," but in fact it's usually the other way around: having alopecia
causes the stress, at least until people find out what it is.
Treatments for
alopecia areata include injecting steroids into affected patches to stimulate
hair growth. This is not practical for large areas. Other treatments, such as
oral steroids or ultraviolet light therapy, are either toxic or impractical. In
most mild cases, patients can comb over the affected areas. In more severe and
chronic cases, some patients wear hairpieces; nowadays some men shave their whole
scalp, now that this look has become fashionable.
Traction alopecia
Tight braids
and ponytails can pull hard enough on hairs to make them fall out. If this
happens, it's best to choose hairstyles that put less pressure on hair roots.
The sooner this is done the better, to avoid permanent damage.
Trichotillomania
This melodramatic name refers to the habit of pulling at hairs or twisting them,
sometimes without realizing it. The scalp and eyelashes are often affected.
Unlike alopecia areata patches, which are perfectly smooth, hair patches in
trichotillomania show broken-off hairs. Treatment is entirely behavioral: You
have to notice that you're doing it and then stop!
Tinea capitis (fungal
infection)
Fungal infection of the scalp for the most part affects school-age
children. Bald spots usually show broken-off hairs. Oral antibiotics are needed
to penetrate the hair roots and cure the infection, after which hair grows back.
Generalized (diffuse) hair loss
Common conditions in this category are:
- telogen effluvium (rapid shedding after childbirth, fever, or sudden weight
loss)
- androgenetic hair loss ("male-pattern baldness," "female-pattern
baldness")
Telogen effluvium
Under normal conditions, scalp hairs live for about
three years (the anagen, or growing, phase); they then enter the telogen, or
resting, phase. During this three-month period, the hair root shrivels up into a
small white "club," then the hair falls out. It is therefore normal to lose
about 100 hairs every day, more of them on days when shampooing loosens the
hairs that are ready to fall out. The hairs are then replaced by the body.
Sometimes people worried about losing their hair start noticing hairs on their
pillow or in the sink, not realizing that they've always been there. A close
look at these will usually reveal the white "club" at the end, showing that
these hairs were already dead. Normally, about 10% of scalp hairs are in the
telogen phase.
There are several circumstances that produce a "shock to the
system" that alters the hair growth rhythm. As a result, as much as 30-40% of
the hairs can cycle into telogen. Three months later hairs come out in a massive
shedding (effluvium), especially near the front of the scalp. These include:
- childbirth
- high fever
- sudden weight loss (crash dieting)
- surgery
None of
these has to be life-threatening, nor does hair loss always follow them. (It can
happen after one pregnancy but not the next.) But when the hair falls out, it's
all over the place--covering the pillow, clogging the drain, and so forth.
Paradoxically, the more dramatic the hair loss, the better the prognosis,
because when the body gets back into normal rhythm, most if not all of that hair
comes back. No special treatment is needed. Normal shampooing can continue,
because this only loosens hairs that were going to come out anyway.
Androgenetic
alopecia ("male-pattern baldness," "female-pattern baldness")
Everyone loses
hair, but men do it better--faster, earlier, and more extensively.
Doctors refer
to common baldness as "androegentic alopecia," which implies that a combination
of hormones and heredity (genetics) is needed to develop the condition. (The
male hormones involved are present in both men and women.)
Male-pattern baldness
Even men who never "go bald" thin out over the years. Unlike those with
reversible telogen shedding, those with common male-pattern hair loss don't
notice much hair coming out; they just see that it's not there anymore.
Adolescent boys notice some receding near the temples as their hairlines change
from the straight-across boys' pattern to the more "M-shaped" pattern of adult
men. This normal development does not mean they are losing hair.
Some "myths"
about male-pattern baldness
- You inherit baldness through your mother's male
relatives. Actually, baldness can come from either side of the family, or both.
Looking at your family can give you at best an educated guess about how you'll
turn out.
- Longer hair puts a strain on roots. They don't. And hats don't choke
off the circulation to the scalp to cause hair loss either.
- Shampooing does not accelerate balding.
- "Poor circulation" does not cause hair loss, and
massaging doesn't stop it.
Next: What treatments are there for hair loss in men? »
 |
 |
From the Doctors at MedicineNet.com  |
 |
 |
- Alopecia Areata - Read about alopecia areata causes, symptoms (bald spot), diagnosis and hair loss treatment (shampoo). Alopecia areata may be hereditary and isn't contagious. Source:MedicineNet
- Thallium - Get the facts about thallium poisoning side effects, health risks and toxicity testing. Learn the metal's characteristic, uses and where it is naturally found. Source:Government
- Read 59 more Hair Loss related articles ...
|
| |
 |
Last Editorial Review: 4/6/2007