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, marijuana or other drugs can cause erectile dysfunction and decreased sexual drive.
Stress, anxiety or depression. Other psychological conditions also contribute to some cases of erectile dysfunction.
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.
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.