A man's penis becomes erect when one of his senses—sight,
sound, taste, touch, or smell—is stimulated and he becomes aroused. His central
nervous system sends nerve impulses that increase blood flow to his penis. As
blood flows into the penis, the penis gets larger and
harder. The blood vessels that drain blood from the penis are blocked enough so
that blood stays in the penis, maintaining the erection.
For a man
to have a normal erection, he needs to have an intact nervous system that
receives external stimulus signals and sends arousal signals to the penis and
an intact system of arteries and veins (vascular system) that allows blood to
flow in and out of the penis.
erection problems are caused by a combination of both
physical and psychological factors.
Physical causes of erection problems
of erection problems may include illnesses, injuries, or complications of
surgery (such as removal of the
prostate for cancer) that interfere with nerve
impulses or blood flow to the penis. When the nervous system cannot transmit
arousal signals, or when the blood vessels in the penis cannot fill or stay
filled with blood, a man cannot have an erection.
of erection problems include:
Problems with the blood vessels (vascular problems).
Psychological causes of erection problems include depression, anxiety,
stress, grief, and problems with relationships. They interfere with the
erection process by distracting the man from things that would normally arouse
him or by lessening the effect they normally have on him.
Psychological issues account for about 40% of erection problems. Erection
problems in men younger than 50 are more likely to be caused by psychological
issues. Psychological causes of erection problems include the following:
A man who loses sexual interest in or
desire for a particular partner may develop erection problems.
man who has been widowed recently may have erection problems.
Some men may have problems having sexual
intercourse with their partner after she has given birth.
(impotence) refers to a man's inability to achieve or maintain an erection that
is sufficient to have sexual intercourse. It does not mean lack of sexual
interest or desire, and the man may or may not be able to have orgasms or
ejaculate. Erectile dysfunction can occur at any age. Occasional episodes are
considered normal and often do not mean there is a serious problem. Doctors prefer the term erectile dysfunction over impotence.
Erectile dysfunction can also be related to another medical condition,
High blood pressure
Liver or kidney disease.
drug abuse or withdrawal.
Pelvic injury or surgery.
Many medicines can cause erectile dysfunction.
Medicines used for erection problems
that cause an erection may be used for erectile dysfunction from physical
problems. They also may be used along with counseling to treat erection
problems that have psychological causes. Most men do not have serious side
effects from these medicines. But if you have an erection that lasts
longer than 3 hours, call your doctor immediately.
Primary Medical Reviewer
William H. Blahd, Jr., MD, FACEP - Emergency Medicine
How this information was developed to help you make better health decisions.