Causes of Erectile Dysfunction

There are many reasons why erectile dysfunction happens. These stem from either psychological (mental) or physiological (physical) concerns, or a combination of both. As a general rule, physical causes are more common in older men while psychological problems are more common in younger men. 

Psychological factors

Erectile dysfunction is often caused by some psychological factor including stress, (anxiety, a new sexual partner or situation), fatigue or unresolved relationship problems. Erectile dysfunction can also be related to a temporary factor, such as the loss of a job, financial concerns or even studying for exams. Erectile dysfunction can also be one outward sign of depression. 

"For a person to become sexually aroused and to function normally, he or she needs to have a feeling of self-confidence, freedom from anxiety, the presence of arousing thoughts or behaviour. Anything that interferes with these conditions can disrupt a sexual encounter. If one or more of these conditions is routinely absent, an inability to perform can become a lasting problem." (From Sexual Health: An interview with a Mayo Clinic Specialist)

Some people don't realize that difficulty getting and/or keeping an erection is a common problem in all men's lives at one time or another. Performance anxiety (worrying about being able to get and keep an erection) can result in ongoing erectile dysfunction - almost like convincing oneself that it IS going to happen. 

In some cases there may be a long-standing or deep-rooted psychological factor. For example, negative attitudes about sex that were taught in childhood or strict religious beliefs can create sexual guilt or anxiety surrounding intercourse. Other factors may include a fear of intimacy, a history of sexual abuse or ambivalence about sexual orientation.

Physiological factors 

About 10 per cent of erection problems are caused by a medical condition or physical problem (The Canadian Medical Association—Home Encyclopaedia, 1992). The most common physical factors are:

  • Diseases  - Some diseases - such as diabetes, kidney disease, liver disease, high blood pressure, chronic alcoholism, multiple sclerosis, atherosclerosis, vascular disease, and neurological disease—can cause damage to the nerves leading to and from the penis. Excessive cycling can cause temporary – and sometimes permanent – erectile dysfunction. The compression of the pudendal nerves against the bicycle saddle is believed to be the most likely explanation of erectile dysfunction in these athletes.\
  • Hardening of the arteries (Atherosclerosis) - When deposits (typically made of cholesterol) build up inside the walls of the arteries, the amount of blood that is able to flow into the penis (causing an erection) is reduced. Cigarette smoking can make this problem worse.
  • Drugs - Drugs used to treat high blood pressure (hypertension), depression, psychosis or anxiety can have an effect on a man’s erections. This is a common cause of erection difficulties in older men who tend to take more of these drugs. Cigarette smoking, marijuana, alcohol or other recreational drugs, if used regularly, can also cause erectile dysfunction.
  • Injuries - Spinal chord injuries and trauma to the nervous system can affect a man’s ability to achieve an erection. These include pinched nerves as a result of slipped vertebral discs or surgical procedures such as prostate cancer removal.
  • Occasionally, erectile dysfunction results from a hormonal imbalance, but this is rare. Hormonal imbalances may include a low level of testosterone (male sex hormone) or diseases of the thyroid, pituitary or adrenal gland.

Diagnosing erectile dysfunction

  • Laboratory tests - Several laboratory tests can help diagnose erectile dysfunction. Tests for systemic diseases include blood counts, urinalysis, lipid profile, and measurements of creatinine and liver enzymes. Measuring the amount of free testosterone in the blood can yield information about problems with the endocrine system and is indicated especially in patients with decreased sexual desire
  • Other tests - Monitoring erections that occur during sleep (nocturnal penile tumescence) can help rule out certain psychological causes of erectile dysfunction. Healthy men have involuntary erections during sleep. If nocturnal erections do not occur, then erectile dysfunction is likely to have a physical rather than psychological cause. Tests of nocturnal erections are not completely reliable, however. Scientists have not standardized such test and have not determined when they should be applied for best results

(Sources: WebMDClinique médicale l’Actuel, MedlinePlus, National Kidney and Urologic Diseases Information Clearinghouse)