As you might expect, there are many possible treatment methods to deal with erectile dysfunction. But one difficulty is that impotence, or erectile dysfunction (the terms mean the same thing), can be both a physical and a psychological problem, and in the latter case the cause and the effect can be hard to separate. For example, is a man's depression caused by his erectile dysfunction, or is it the other way round? You might expect erectile dysfunction to cause depression, for it takes away a man's sense of his masculinity, yet it's also true that depression can cause a man to lose both his interest in sex and his erections.

The most common physical cause of erectile dysfunction is impairment of blood flow - either in or out of the penis. Other common causes are nerve damage due to diabetes, and cholesterol blocking the small arteries of the penis. Some physical problems like this can be helped by surgery.

There's an easy way to tell if you have a physical problem or a psychological one: if you have night time erections then there's not likely to be much wrong with the structure and function of your penis; you most likely have a psychological cause for the problem. Most men get between three and five erections per night, although this gets less as a man gets older.

Of course, the way you live has an impact on the vigour and health of your erections. Smoking, excess drinking, stress, being overweight, poor physical fitness and poor lifestyle, especially drug use and inadequate food, can seriously hamper sexual performance. As if that wasn't bad enough, some prescription drugs can have the same effects. Here's a summary of the causes of erectile dysfunction:

Psychological causes: stress, relationship or family problems, employment worries, depression, and anxiety.

Physical: hormone problems, drugs, vascular disease, high blood pressure, nerve disorders, surgery to the pelvis or genital areas, radiation therapy, chronic illness. Hormone problems are quite common but often not recognised: a man's hormone levels decline slowly by thirty to forty percent between the ages of forty five and seventy. Drugs: blood pressure medication, antidepressants, anti-psychotics, anti-androgens and others, including stomach medication and painkillers. But although this may seem very complicated, most erectile dysfunction can be treated at home with the same methods used by professional sexual therapists.

If you seek help for erectile dysfunction, the first step will be for a doctor to take a complete medical history and look into any of the possible causes listed above. One of the key things is to establish if you have nocturnal erections. Believe it or not, the simplest test for nocturnal erections is to fasten a strip of gummed postage stamps around the penis: the strip will be broken in the morning if the penis becomes erect during the night. But despite the simple nature of this test, it is very useful, for having normal erections means there may be no physical problem in the penis.

So if a man's erectile dysfunction is caused by psychological factors, how can it be treated? There are four categories of treatment, which can be summed up as follows: lifestyle and medication changes; medical treatment or surgery; and, most importantly, psychosexual therapy.

Much of this is common sense. Healthy exercise, good food and a balanced diet, not smoking, and low alcohol intake are all key points. If you're taking drugs for a particular medical condition, they can be changed for another that has less effect on your erections. Surgery can be tried in the cases with a clear physical cause, but most useful is good sexual psychotherapy. We know that the majority of cases of erectile dysfunction can improve dramatically with psychological therapy. Professional sex therapists will use a treatment system that focuses on making a man more relaxed, reducing his anxiety and increasing his sense of connection to his own body. A lot of men who have erection problems tend to use fantasy a lot to maintain their arousal during sex. But relying on fantasy to stay erect becomes less effective as a man gets older because his natural ability to stay sexually aroused without physical contact decreases. So a lot of the therapy is about helping a man to learn that he needs physical touch from his partner to keep his erection. What's more, the touch has to be the right kind of touch, so both the man and his partner need to learn the techniques.

It comes down to this: male and female sexual arousal both depend, ultimately, on physical stimulation. So a man with erectile dysfunction can often regain his sexual potency when he and his partner learn to touch each other in the right way. Of course, he also needs to learn how to be relaxed and reduce any anxiety around sex - this includes fear of failure, fear of ejaculating too soon, and fear of not being good enough.