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Hair
Loss Canada > Hair Loss Information
Male
Pattern Baldness
Although there are many causes of
hair loss, most cases are due to androgenic alopecia (AGA) or Male
Pattern Baldness (MPB),which accounts for approximately 95% of all
hair loss among males. It's believed to be caused by a combination
of three factors:
- Age
- Heredity
- Testosterone (male hormone)
Men over 50 and postmenopausal
women experience some degree of androgenetic alopecia. In men hair
loss usually occurs at the front and at the vertex of the scalp.
In women with AGA, hair loss is not as localized.
Androgenic Alopecia
or Male Pattern Baldness (MPB)
Signs and Symptoms
- Receding hairline
- Moderate to extensive loss of hair,
especially on the crown
MPB is the hair loss most
frequently encountered. It usually starts with the hair at the
temples, which gradually recedes to form an "M"
shape. Hair becomes finer and does not grow as long as it
once did. At the same time or later, hair loss exposes the crown
of the head. As the condition progresses, the point of the
"M" continues to recede, while the bald spot at the
crown widens. Eventually, the thinning crown and receding point
may meet. Over time, you are left with a horse-shoe pattern of
hair around the sides of your head. Any remaining hair in the
balding areas usually manifests some miniaturization - it is
thinner and grows at a below-normal rate, changing from long,
thick, coarse, pigmented hair into fine, unpigmented sprouts.
A receding hairline reflects age,
but not necessarily great age, since some men start balding quite
young. With the spurt in androgen secretion at puberty, the
hairline moves back a little in 96 per cent of boys and 80 per
cent of girls. Most boys continue to shed hair as they mature and,
if baldness runs in the family, lose increasing amounts. By age 35
to 40, two thirds of Caucasian men are noticeably bald. The loss
may begin at age 20, then stop, only to start up again a few years
later. Since this type of baldness is largely hereditary, a man
can usually, although not always, predict the extent of his future
baldness by examining family portraits. About 50 per cent of
children with a balding parent of either sex will inherit the
dominant baldness gene.
Research shows that a male hormone,
dihydrotestosterone (DHT) — a derivative of testosterone
produced from testosterone by an enzyme called 5 alpha-reductase,
plays a vital role in hair loss in men. Hair follicles at the top
and front of heads as well as temples are particularly sensitive
to DHT. Genetically sensitive hair follicles shrink when exposed
to DHT. As the follicles become smaller, the hair growing Anagen
phase shortens and the resting Catagen and Telogen phases
lengthen. The hair becomes increasingly thinner, shorter and less
deeply rooted. Eventually, hair growth stops.
Other Causes of Hair Loss
Although Male Pattern Baldness (MPB)
among adult males is most noticeable and widespread, people of all
ages and both sexes may experience hair loss problems due to any
of a variety of causes.
Alopecia
Areata, a condition in which hair comes out by the roots
in one or more spots, is much less common than MPB. It generally
strikes first during childhood or early adulthood. Sometimes
called patchy baldness, Alopecia Areata may clear up on its own or
progress to the point where the person loses all scalp hair
(Alopecia Totalis), or even body hair, including eyelashes and
eyebrows (Alopecia Universalis).
Although the exact
cause is not known, some experts believe Alopecia Areata may
involve an immunological disorder, which causes the body to
produce antibodies that attack the hair follicles. Other evidence
suggests that Alopecia Areata may be in some cases, a hereditary
condition.
Hair loss may also be
caused by seborrhoea, scalp infections, nutritional inadequacy or
deficiency, systemic illness, fever, severe stress, etc.
You should always
consult your doctor if you are concerned about excessive hair loss
and baldness.
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Loss Information
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