Outline
The
Bare Facts About Normal Hair Loss
Hair Today, Gone Tomorrow
Causes of Hair Loss
See Your Doctor
At my clinic, I often hear the following complaints from
men that come to see me:
“When I wake up in the morning, my pillow is covered
with hair!” or “I’m pulling hairs out of the shower drain by the
handful!” Does that sound like you? If so, then welcome to the world
of the “follically challenged.” You are certainly not alone: 2 out of every
3 men suffer from hair loss by the age of 60. In this article, I will focus
on the various causes of hair loss.
The Bare Facts About Normal
Hair Loss
Before we begin to tackle the many causes of hair loss,
you should understand how your hair is supposed to grow. Scalp hair grows
about one-half inch per month but slows down as we age. The average human
scalp is covered by about 100,000 hair follicles! At any given time,
about 90% of these follicles are in a growing phase, which lasts anywhere
from 2 to 6 years. The other 10% of your hair is in a resting phase that
lasts 2 to 3 months. At the end of this resting phase, this hair is shed.
On a typical day, 50 to 100 hairs are shed through normal activities, such
as shampooing, combing, and brushing. Fortunately for us, after a hair
is shed, a new hair from the same follicle replaces it, and the growth
cycle begins anew.
So long will my hair last? That depends on your follicles.
Each follicle is genetically programmed to go through a particular number
of growth cycles before it finally dies. This number varies from follicle
to follicle and from person to person, our individual differences
in hair growth and, in many instances, lack thereof.
Hair
Today, Gone Tomorrow
Let me take you through a typical evaluation of a patient
with hair loss. First, I would ask you a series of questions about whether
you have any chronic diseases or recent illnesses, about your diet and
the medications you currently take (including over-the-counter agents such
as vitamins), your family history of hair loss, and your hair care routine
and styling habits. Next, I would examine both your scalp and hair, and
I may pluck a few hairs to observe them under a microscope. Depending on
what I find, I may ask you to have some laboratory tests, such as blood
work or even a biopsy or sample of your scalp.
Causes
of Hair Loss
There are many potential causes of hair loss. It is important
to determine the cause of your hair loss because the cause will usually
determine the type of treatment you should have.
Male pattern baldness
Male pattern baldness, also known as androgenetic alopecia,
is a hereditary form of hair loss. Male pattern baldness is by far the
most common cause of hair loss, affecting over 20 million men in the United
States. To fully understand what goes on in male pattern baldness, let’s
briefly revisit the hair cycle. Over time, some hair follicles begin to
shrink, producing finer, shorter hairs (“peach fuzz”). This is what accounts
for thinning of the scalp. These changes usually start at the temples,
appearing as the classic “receding hairline.” It also occurs on the crown
of the scalp. Eventually, hair follicles may begin to die, leading to hair
loss. Bald spots may increase in size until the entire top of the head
is bald with hair remaining only on the sides. (Fortunately, there are
several medical and surgical treatments for androgenetic alopecia.)
If you are like a lot of my patients, you may believe
the myth that your hair loss is inherited from your mother’s side of the
family. But for many men who are losing their hair, their mother’s father
has a full head of hair. So then why are they going bald? The truth is,
baldness is a very complicated genetic trait that may be inherited from
either the mother’s or father’s side of the family (or both). And it can
even skip generations. So, please, don’t blame your mother!
Medication
An annoying side effect of certain medications may be
temporary hair loss in a small percentage of patients. Examples of the
more common drugs known to have this effect include certain blood pressure
medications (beta blockers such as Inderal®), blood thinners (warfarin
and heparin), as well as some of the medications used to treat gout, arthritis,
and heart problems. Also, high doses of vitamin A may also cause hair loss
which is reversible.
Chemotherapy
Many agents used to treat cancer will cause hair cells
to stop dividing, stopping hair growth. Up to 90% of the hairs may fall
out 1 to 3 weeks after cancer treatment. Fortunately, the hair does regrow
in most cases when the treatment is completed. Cancer patients should be
warned of this side effect so that they have the opportunity to prepare
for any possible hair loss, such as getting a wig or hairpiece, if desired,
prior to treatment.
Tinea capitis
Tinea capitis, or ringworm, is a fungal skin infection
that can cause a patchy form of hair loss when the scalp is infected.
A ringworm scalp infection results in hairs breaking off at the surface
of the scalp. There may be redness, flaking, scaling, swelling, and even
oozing at the affected areas on the scalp. And there is often itching and
pain as well. Severe cases of ringworm may lead to swollen glands in the
neck or back of the head.
Ringworm is a contagious form of hair loss, most common
in children. It is spread by contact, such as sharing brushes, towels,
and hats, and is commonly spread from child to child at daycare centers
or schools. Some strains of tinea capitis can also be contracted from pets,
particularly cats. Fortunately, this infection is curable with oral antifungal
medication, and it is important that all affected family members, classmates,
and pets be treated to prevent reinfection.
Alopecia areata
Alopecia areata appears as discrete, smooth, round patches
of hair loss about the size of a coin or larger. There may be one or several
of these coin-sized patches of hair loss. This condition is most often
limited to one area of the body but can affect the scalp, beard, eyebrows,
eyelashes, or any hair on the body. A severe form of this disease,
known as alopecia universalis, results in total loss of all scalp and body
hair. Fortunately, this is rare.
The cause of alopecia areata remains a mystery. It is
not uncommon, affecting approximately 2% of the population. It may occur
at any age and is equally common among women and men. Besides the hair
loss, affected persons are usually otherwise healthy. In some cases, the
bald area(s) will spontaneously regrow hair over several months without
treatment. In other cases, the bald spots may progressively enlarge.
There are various topical treatments available for alopecia
areata, which may be beneficial in some cases. In my practice, I have found
that the most effective treatment for localized bald spots is the injection
of a steroid solution directly into the involved areas. The steroid solution
remains localized to the injected areas and is not absorbed in the body
in large enough amounts to cause any side effects. These injections can
be repeated at monthly intervals until there is a cosmetically acceptable
regrowth of hair.
Telogen effluvium
Telogen effluvium is a condition characterized by a generalized,
diffuse hair loss that occurs 2 to 3 months after a significant stress
on the body, such as major surgery, severe illness, or even crash dieting.
Any severe shock to the system can cause more than 20% of our hair follicles
to enter into the resting phase of the hair cycle, rather than the normal
10%, as previously discussed. As a result, more hairs are shed than usual,
which leads to significant thinning of hair. The good news is that in most
cases, these hairs will return to their growing phase within a few months,
but it will take longer for the thin areas to fill in. I counsel my patients
not to expect a return to their normal head of hair for at least 6 months.
Other causes
Iron deficiency (anemia) as well as thyroid disease (either
an underactive or overactive thyroid) can result in hair loss. Your doctor
may order specific laboratory tests to check for these conditions. Hair
loss that is associated with either anemia or thyroid disease is reversible
with proper treatment.
See Your
Doctor
If your hair is shedding in large amounts after brushing
or combing, or if you notice that your hair is thinning, you should consult
your doctor. If you are experiencing hair loss, it is very important that
you find out the cause. Although usually genetic in nature, certain forms
of hair loss may signal a disease process. Also, the treatment best for
you will vary, depending on the cause of your hair loss.
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