The process of achieving an erection is complex, and
problems may occur for a variety of reasons. These problems can be
psychological, physical or a combination of the two.
Physical causes of ED are related to a breakdown or
damage to the sequence of events that leads to an erection. This sequence
involves nerve impulses in the brain, spine and penis as well as the subsequent
response in the muscles, fibrous tissues, veins and arteries in and near the
corpora cavernosa.
In some cases, the breakdown or damage in the sequence
of events affects the arteries, muscles and surrounding tissues of the penis.
This breakdown is most commonly the result of a disease. Diseases that commonly
cause ED include:
- Diabetes: Diabetes can cause nerve and artery damage that can make
achieving an erection difficult. Between 35% and 50% of men with diabetes
experience ED.
- Kidney disease: Kidney disease can cause chemical changes that
affect hormones, circulation, nerve function and energy level. These changes
can lower libido (sex drive) or sexual ability. Drugs used to treat kidney
disease may also cause ED.
- Neurological (nerve and brain) diseases: The nervous system plays a
vital part in achieving and maintaining an erection. It is common for men
with conditions such as stroke, multiple sclerosis (MS), Alzheimer’s
disease, Parkinson’s disease and spinal cord injuries to experience ED. This
is due to an interruption in the transmission of nerve impulses between the
brain and the penis.
- Vascular disease: Vascular diseases are those that affect the blood
vessels. These diseases include atherosclerosis (hardening of the arteries),
hypertension and high cholesterol. These diseases, which account for 70% of
physical-related causes of ED, restrict blood flow to the heart, the brain
and--in the case of ED-- to the penis. Atherosclerosis alone accounts for
50%-60% of ED cases in men over age 60.
- Prostate cancer: Prostate cancer doesn’t cause ED on its own, but
treatment for prostate cancer can lead to erectile problems.
The physical causes of ED are not only disease-related. There are many other potential causes, including:
- Surgery: Surgery performed to treat diseases such as prostate cancer
and bladder cancer often require the removal of nerves and tissues around
the affected area. Some of these surgeries result in only temporary
problems (lasting 6-18 months), while others result in permanent damage to nerves and tissue.
- Injury: Injuries to the pelvis, bladder, spinal cord and penis that
require surgery also commonly cause ED.
- Hormonal imbalances: Hormonal causes of ED account for only 5% of
all cases of ED. Imbalances of hormones such as thyroid, prolactin and
testosterone, can affect a man’s response to sexual stimulation. These
imbalances can be the result of a tumor on the pituitary gland, kidney disease or liver disease.
- Venous leak: If the veins in the penis cannot prevent blood from
leaving the penis during an erection, an erection cannot be maintained. This
is known as a venous leak, and can be a result of injury, disease or stress.
- Tobacco, alcohol or drug use: All three of these substances can
damage a person’s blood vessels and/or restrict blood flow to the penis,
causing ED. Smoking in particular plays a large role in causing ED in people with arteriosclerosis.
- Prescription drugs: There are over 200 types of prescription drugs that may cause ED.
Sources:
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