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What
is Erectile Dysfunction?
Erectile
dysfunction (ED) is the inability of a man to achieve or
maintain an
erection sufficient for his sexual needs or the needs of his partner.
Most men
experience this at some point in their lives, usually by age 40, and
are not
psychologically affected by it.
Some
men, however, experience chronic,
complete erectile
dysfunction (impotence), and others, partial or brief
erections.
Frequent erectile dysfunction
can cause emotional and relationship
problems,
and often leads to diminished self-esteem. Erectile dysfunction has
many
causes, most of which are treatable, and is not an inevitable
consequence of
aging. An erection
occurs due to hydraulic effects due to blood entering and
being
retained in sponge-like bodies inside the penis.
During
intercourse,
the
process is initiated when sexual arousal is transmitted from the brain
to
nerves in the pelvis. There are various and often multiple underlying
causes,
some of which are treatable medical conditions. The most important
organic
causes are cardiovascular disease and diabetes, neurological problems
(for
example, trauma from prostatectomy surgery), hormonal insufficiencies
(hypogonadism) and drug side effects. It is important to realise that erectile
dysfunction can signal underlying risk for cardiovascular
disease.
There is
often a
contributing and complicating and sometimes a primary psychological or
relational problem. Psychological impotence is where erection or
penetration
fails due to thoughts or feelings (psychological reasons) rather than
physical
impossibility; this can often be helped. Notably in psychological
impotence,
there is a strong response to placebo treatment. Erectile dysfunction,
tied
closely as it is to cultural notions of potency, success and
masculinity, can
have severe psychological consequences. There is a strong culture of
silence
and inability to discuss the matter. In reality, it has been estimated
that
around 1 in 10 men will experience recurring Erectile Dysfunction problems at
some
point
in their lives.
Besides
treating the
underlying causes and psychological consequences, the first line
treatment of erectile
dysfunction consists of a trial of PDE5 inhibitor drugs (the
first of
which was
sildenafil or Viagra). In some cases, treatment can involve
prostaglandin
tablets in the urethra, intracavernous injections with a fine needle
into the
penis that cause swelling, a penile prosthesis, a penis pump or
vascular
reconstructive surgery.
The study of
erectile
dysfunction within medicine is covered by andrology, a sub-field
within
urology.
Incidence
and Prevalence Of
Erectile Dysfunction
The term
"erectile
dysfunction" can mean the inability to achieve erection, an
inconsistent
ability to do so, or the ability to achieve only brief erections. These
various
definitions make estimating the incidence of erectile dysfunction
difficult.
According to the National Institutes of Health in 2002, an estimated 15
million
to 30 million men in the United States experience chronic erectile
dysfunction.
According to
the National
Ambulatory Medical Care Survey (NAMCS), approximately 22 out of every
1000 men
in the United States sought medical attention for Erectile Dysfunction
in 1999.
Incidence of
the disorder
increases with age. Chronic Erectile
Dysfunction affects about 5% of
men in their 40s and 15–25%
of men by the age of 65. Transient Erectile Dysfunction and inadequate
erection affect as many as
50% of men between the ages of 40 and 70.
Diseases
(e.g., diabetes,
kidney disease, alcoholism, atherosclerosis) account for as many as 70%
of
chronic Erectile Dysfunction
cases and psychological factors (e.g.,
stress, anxiety, depression)
may account for 10–20% of cases. Between 35 and 50% of men with
diabetes
experience ED.
Anatomy
of the Penis
The internal
structure of
the penis consists of two cylinder-shaped vascular tissue bodies
(corpora
cavernosa) that run throughout the penis; the urethra (tube for
expelling urine
and ejaculate); erectile tissue surrounding the urethra; two main
arteries; and
several veins and nerves. The longest part of the penis is the shaft,
at the
end of which is the head, or glans penis. The opening at the tip of the
glans,
which allows for urination and ejaculation, is the meatus.
Physiology
of Erection
The
physiological process of
erection begins in the brain and involves the nervous and vascular
systems.
Neurotransmitters in the brain (e.g., epinephrine, acetylcholine,
nitric oxide)
are some of the chemicals that initiate it. Physical or psychological
stimulation (arousal) causes nerves to send messages to the vascular
system,
which results in significant blood flow to the penis. Two arteries in
the penis
supply blood to erectile tissue and the corpora cavernosa, which become
engorged and expand as a result of increased blood flow and pressure.
Because
blood must stay in
the penis to maintain rigidity, erectile tissue is enclosed by fibrous
elastic
sheathes (tunicae) that cinch to prevent blood from leaving the penis
during
erection. When stimulation ends, or following ejaculation, pressure in
the
penis decreases, blood is released, and the penis resumes its normal
shape.
Overview and symptoms of
Erectile Dysfunction
Erectile
dysfunction is
characterized by the regular or repeated inability to obtain or
maintain an
erection. There are several ways that erectile
dysfunction is analyzed:
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Obtaining
full erections at
some times, such as when asleep (when the mind and psychological
issues, if any,
are less present), tends to suggest the physical structures are
functionally
working. However, the opposite case, a lack of nocturnal erections,
does not
imply the opposite, since a significant proportion of sexually
functional men
do not routinely get nocturnal erections or wet dreams.
Obtaining
erections which
are either not rigid or full (lazy erection), or are lost more rapidly
than
would be expected (often before or during penetration), can be a sign
of a
failure of the mechanism which keeps blood held in the penis, and may
signify
an underlying clinical condition, often cardiovascular in origin.
Other
factors leading to erectile
dysfunction are diabetes mellitus (causing neuropathy) or
hypogonadism
(decreased testosterone levels due to disease affecting the testicles
or the
pituitary gland).
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