Cause
Erection problems (erectile dysfunction) may be caused by physical problems
related to the blood vessels, nerves, and hormones or by psychological issues.
Current evidence suggests that physical causes account for about 80% of
erection problems.1
Normally, an erection
occurs when your imagination or senses (vision, hearing, touch, smell, taste)
are stimulated and you become aroused. Your central nervous system sends nerve
impulses that increase blood flow to your penis. Blood fills the spongy
chambers (corpora cavernosa) in the penis, causing them to expand and become
rigid.
Four requirements for a normal erection are:
- A properly functioning nervous system that
sends the necessary signals to the penis.
- An intact system of blood
vessels (vascular system) to allow blood to flow into and out of the
penis.
- Normal smooth muscle in the penis, which must relax so the
penis can fill with blood and enlarge.
- The ability to trap the
blood in the penis so that it stays firm.
Physical causes of erection problems
include long-term (chronic) and short-term (acute) injuries and complications
of
prostate or other surgery that interfere with nerve
impulses or blood flow to the penis. Physical problems are often the cause of
erection difficulties in men age 50 or older.
- Problems with the blood vessels (vascular problems) may prevent blood from filling the penis or from remaining
there long enough to maintain an erection. For example, long-term
high blood pressure can cause damage to blood vessels
and lead to erection problems.
- Problems with the nerves (neurologic
problems) may prevent arousal signals from traveling from the brain and spinal
cord to the penis. Nerve disorders such as
Parkinson's disease,
Alzheimer's disease,
multiple sclerosis, and
stroke may interfere with a man's ability to have an
erection and may lower sexual desire. Nerve damage from
diabetes, complications from surgery, and spinal cord
injury also may cause problems.
- Problems with the structure of the
penis or its surrounding tissues may prevent an erection.
- Hormonal factors, such as a low level of the hormone
testosterone, may be involved in causing erection
problems.
- Side effects of medications (for example, some of
those taken for high blood pressure or
depression) may include erection problems. In some
cases it may be possible to change the dose of the medicine or to use another
medicine.
- The use of tobacco, alcohol, or illegal drugs can lead to
erection problems. Stopping or reducing the use of these substances may reduce
the severity of a man's erection problem.
Activities that restrict blood flow to the penis also may
result in erection problems. Some doctors have observed that men who regularly
ride bicycles over long distances are more likely to have erection problems
than men who ride only occasionally, especially if they ride on a narrow,
unpadded saddle. But the possible link between bicycle riding and erection
problems has not been proven.
A
vasectomy usually does not cause an erection problem.
But pain after the operation may affect sexual performance for a time, and if a
man was not comfortable with his decision to have a vasectomy, or is having
second thoughts, it could affect him psychologically.
Psychological causes of erection problems include depression
(which also has a physical component),
anxiety,
stress,
grief, or problems with current or past relationships.
These interfere with the erection process by distracting the man from things
that would normally arouse him. Erection problems in men younger than 40 who
have no physical risk factors are more likely to be caused by psychological
factors than physical causes.
- Relationship problems can lead to erection
problems. This may happen when a man has been widowed or loses sexual interest
in a particular partner.
- Some men develop erection problems when
they contemplate marriage.
- Some men may have difficulty having
sexual intercourse with their partner after their first child is born.