Causes of Hair Loss
There are many causes of baldness (alopecia), however the most
common cause is male pattern baldness (androgentic alopecia.) You should consult
a doctor specializing in hair loss and therapy to determine the cause of your
hair loss.
Male Hair Loss & Pattern Baldness in Men
By some estimates, more than 35 million men, in the United
States, are affected by male pattern baldness (androgenetic alopecia) "Andro" refers to
the androgens (testosterone, dihydrotestosterone) necessary to produce male-pattern
hair loss (MPHL). "Genetic" refers to the inherited gene necessary
for MPHL to occur. In men who develop male pattern baldness the hair loss may
begin any time after puberty when blood levels of androgens rise. The first change
is usually recession in the temporal areas, which is seen in 96 percent of mature
Caucasian males, including those men not destined to progress to further hair
loss.
Knowledge, of hair loss and its causes, has increased
exponentially over time. Hamilton and later Norwood have classified the patterns
of male pattern baldness (see illustration below). Although the density of hair
in a given pattern of loss tends to diminish with age, there is no way to predict
what pattern of hair loss a young man with early male pattern baldness will eventually
assume. In general, those who begin losing hair in the second decade are those
in whom the hair loss will be the most severe. In some men, initial male-pattern
hair loss may be delayed until their thirties or forties. Generally, men in their
20’s have roughly,
a 20 percent incidence of male pattern baldness, and the incidence and severity
of hair loss increases in later years.
Hamilton first noted that androgens (testosterone, dihydrotestosterone) are
necessary for the development of male pattern baldness. The amount of androgens
present does not need to be greater than normal for male pattern baldness to
occur. If androgens are present in normal amounts and the gene for hair loss
is present, male pattern hair loss will occur. Axillary (under arm) and pubic
hair are dependent on testosterone for growth. Beard growth and male pattern
hair loss are both dependent on dihydrotestosterone (DHT).
Hair Growth Cycle
Each hair sits in a cavity in the skin called a follicle.The life of an individual
hair is about 6 years. The hair grows about a half an inch per month. At any
one time about 85 percent of the hairs are in a growth stage and the rest are
dormant, and falling out, with a new hair growing in its place. Iin men who are
balding, the follicle fails to produce a new hair. Why this occurs is not well
understood, but it is related to your genes and male sex hormones. Even though
the follicles are small, they remain alive, suggesting the possibility of new
growth. When androgenetic alopecia is present, the percentage of hairs in the
growth phase (anagen) and the duration of the growth phase decrease, resulting
in shorter and thinner hairs. More hairs are in the dormant state (telogen) and
these hairs are increasingly subject to loss with the daily trauma of washing,
brushing and combing. The hair shafts in male pattern baldness become progressively
shorter and thinner, with time.
Pigment (color) production may also decrease simultaneously.
The affected areas can completely lose all follicles over time. Male pattern
baldness is an inherited condition and the gene can be inherited from either
the mother or father’s
side. There is a common myth that inheritance is only from the mother’s
side. This has been proven to be untrue.
In summary, male pattern hair loss (Androgenetic Alopecia)
is an inherited condition manifests itself when androgens are present in normal
amounts. The gene can be inherited from the mother or father’s side. The
onset, rate, and severity of hair loss vary from one individual to the next.
The severity does increase with age. When the condition is present, it will increase
in severity over time.
Male Pattern Baldness, or androgenetic alopecia, is likely
to occur primarily between late teen-age years and age 40-50. Men who have relatives
with this condition may well expect to suffer from the condition as well.
Norwood-Hamilton Scale of Male Pattern Baldness
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