For an erection to occur, several parts of the body must work together. The brain sends messages to control the nerves, hormone levels, blood flow and muscles that cause an erection. If anything interferes with these messages, or if any part of the system doesn't function correctly, an erection won't occur.

The penis has two sponge-like cylindrical structures that run along its length, parallel to the urethra (the tube that carries semen and urine). During sexual arousal, these cylinders become engorged with blood, straightening and stiffening the penis. Continued sexual arousal maintains the higher rate of blood flow into the penis and limits the flow out of the penis, keeping the erection firm. After ejaculation or when the sexual excitement passes, the excess blood drains out of the spongy tissue and the penis returns to its non-erect size and shape.

All people with penises will have difficulties with erections from time to time. The occasional failure to get or maintain an erection, which lasts long enough to have sex, can occur for a variety of reasons, including drinking too much alcohol or being very tired. The inability to get or maintain an erection less than 20% of the time is not unusual.

Erectile dysfunction (ED) is the inability to get or maintain an erection 25% or more of the time. Some people with ED find they are completely unable to achieve an erection, others have an inconsistent ability to achieve an erection, and still others experience only brief erections. ED is a frustrating condition that can have physical or psychological causes. ED can be the first sign of an underlying health condition that needs treatment, so seeking medical evaluation is important.

ED is also different from a lack of sexual desire or problems with ejaculation and orgasm.

Erectile dysfunction affects 30 million people in the United States. The problem can occur at any age, but the older a person gets, the greater the chance of developing a health problem that results in ED. According to the National Institutes of Health, among people with penises, approximately 5% of 40-year-olds and between 15 and 25% of 65-year-olds experience ED on a long-term basis.

In young people, erectile dysfunction is less common and when it does occur is more likely to have a psychological cause such as stress or performance anxiety. Still, younger people are seeking treatment for this and other sexual problems in increasing numbers. The use of Viagra increased 312% among people aged 18-45 between 1998 and 2002.

A number of things can interfere with sexual feelings and lead to or exacerbate erectile dysfunction. These can include:

• Depression
• Anxiety
• History of physical, emotional, or sexual abuse
• Stress
• Fatigue
• Poor communication or conflict with your partner

Erectile dysfunction as a result of a psychological cause tends to develop rapidly and be related to a recent situation or event. You may find you are able to have an erection in some circumstances but not in others. If you are generally able to experience or maintain an erection when you first wake up in the morning this can suggest that the problem is psychological rather than physical. 

While thoughts and emotions always play a role in getting an erection, erectile dysfunction is most often caused by something physical, such as a chronic health problem or the side effects of a medication. The physical and psychological causes of erectile dysfunction interact. For instance, a minor physical problem that slows sexual response may cause anxiety about maintaining an erection. The resulting anxiety can worsen erectile dysfunction.

A variety of physical risk factors can contribute to erectile dysfunction. Factors that may be present for younger men include:

Substance abuse

Chronic use of alcohol, cannabis or other drugs can cause erectile dysfunction and decreased sexual drive. Learn about substance abuse

Stress, anxiety or depression

Other psychological conditions also contribute to some cases of erectile dysfunction. Learn about stress

Smoking

Smoking can cause erectile dysfunction because it restricts blood flow to veins and arteries. People who smoke cigarettes are much more likely to develop erectile dysfunction. Learn about smoking

Having a chronic health condition

Diseases of the lungs, liver, kidneys, heart, nerves, arteries or veins can lead to erectile dysfunction. So can endocrine system disorders, particularly diabetes. The accumulation of deposits (plaques) in your arteries (atherosclerosis) also can prevent adequate blood from entering your penis. And in some people, erectile dysfunction may be caused by low levels of testosterone.

Taking certain medications

A wide range of drugs - including antidepressants, antihistamines and medications to treat high blood pressure, pain and prostate cancer - can cause erectile dysfunction by interfering with nerve impulses or blood flow to the penis. Tranquilizers and sleeping aids also can pose a problem.

Certain surgeries or injuries

Damage to the nerves that control erections can cause erectile dysfunction. This damage can occur if you injure your pelvic area or spinal cord. Surgery to treat bladder, rectal or prostate cancer can increase your risk of erectile dysfunction.

Prolonged bicycling

Over an extended period, pressure from a bicycle seat has been shown to compress nerves and blood flow to the penis, leading to temporary erectile dysfunction and penile numbness.

Metabolic syndrome

This syndrome is characterized by unhealthy cholesterol and triglyceride levels, high blood pressure, and insulin resistance.

Whether the cause is physical factors or psychological factors or a combination of both, erectile dysfunction can become a source of mental and emotional stress for you - and your partner(s). If erectile dysfunction is more than a temporary, short-term problem, see your medical provider.

Brown students can make an appointment at Student Health Services by calling 401.863-3953. You can request specific providers by name or by gender. Your provider can help you determine the underlying cause or causes of erectile dysfunction and then help you find the right type of treatment.

If you experience occasional or persistent erectile dysfunction, your partner(s) may see your inability to have an erection as a sign of diminished sexual desire. Your reassurance that this is not the case can help. Try to communicate openly and honestly about your condition. Treatment is often more successful if partners address the issue together.

Although most people with penises experience episodes of erectile dysfunction from time to time, you can take these steps to decrease the likelihood of occurrences:

• Exercise regularly.
• Reduce and manage stress.
• Get enough healthy sleep.
• Get help for anxiety or depression.
• Limit or avoid the use of alcohol.
• Avoid recreational drugs, including cannabis.
• Stop or reduce smoking.
• See your medical provider for regular checkups and medical screening tests.
• Work with your medical provider to manage conditions that can lead to erectile dysfunction, such as diabetes and heart disease.

For psychological causes, seeking treatment from a mental health professional or from a sex therapist can be very helpful. If you are a Brown student, you can seek help from Counseling and Psychological Services for issues including stress, depression, and anxiety. AASECT maintains a list of certified sex therapists across the country.

For physical causes, a wide variety of treatments are available, depending on the specific physical issue. The first step is often to try ED medications, like Viagra, since these help most men. Depending on your diagnosis, other treatments range from changing your prescription drugs to hormone replacement therapy, antidepressant therapy, and devices, medications or implants to produce erections. 

In assessing whether you have premature ejaculation, it can be important to ask whether your own or your partner's stamina expectation is realistic. Keep in mind that the average time from insertion to ejaculation is less than three minutes.

If your partner is person with a vulva, remember that they may not orgasm automatically as a result of prolonged intercourse. Surveys tell us that only about one fourth to one half of people with vulvas regularly orgasm during intercourse. Most find it is easier to be orgasmic with manual or oral stimulation than through intercourse.

Learn More About Premature Ejaculation