Male Erectile Dysfunction

Male erectile dysfunction, or impotence as it was previously known, is the inability to maintain an erection that is sufficiently hard or that fails to last long enough for satisfactory sexual intercourse for both partners. It is important to know that premature ejaculation is not necessarily a sign of erectile dysfunction. Low sex drive (poor libido) can be associated with erectile dysfunction, particularly if there is an underlying hormonal disorder, but in the majority of cases, the patient seeks advice because libido is maintained while performance is not.

It is a common problem that men suffer, causing progressive difficulty with increasing age. Overall, approximately 1 man in 10 is affected by ongoing erectile dysfunction. Many early estimates of the frequency of erectile dysfunction came from the Massachusetts Male Ageing Study, which probably underestimated the frequency of problems. A more recent study of 1661 men in the Netherlands found much higher rates with up to 20 per cent of men between 50 and 54 years and 50 per cent of men between 70 and 74 years having some problems with erections.

What causes erectile dysfunction?

An erection is a complex process. To achieve and maintain a good erection, four parts of the body need to function well.

- The hormonal environment needs to be right.
- Several systems of nerves need to interact effectively.
- Two systems of blood vessels (arteries and veins) must function well.
- The man's state of mind, which overlays and influences the process.

To start an erection, the brain sends messages that control hormone levels, the nerves and the blood vessels. If any factors interfere with this messaging system, one of these parts of the system will fail and a poor quality erection will result.

The first visible part of an erection is called the tumescent stage. During this stage, the cavernosal bodies (corpora cavernosa) in the shaft of the penis start to fill with blood and the penis becomes swollen but is not usually hard enough for sex.

As these cavernosal bodies fill up with blood, they squash the veins within the penis against the fascia (membranes) inside the penis. Blood is trapped within these blood vessels, which makes the penis hard and erect.

Erectile dysfunction can have either a physical or a psychological cause. Most commonly, both causes contribute to difficulties. Psychological causes include stress, depression or any form of anxiety. Erectile difficulties can in themselves cause a psychological state ('performance anxiety') that increasingly interferes with the erectile process. Although psychological factors often contribute to the problem in all age groups, physical causes become more common with increasing age. As a general rule, erectile dysfunction due to psychological causes has a more sudden onset than that caused purely by physical factors, which develops more progressively.