It affects somewhere between fifteen to twenty million men in the United States alone. Although erectile dysfunction occurs most often in older men it is a common problem and can affect any man at any age.

A man's inability to keep an erection every now and then may not be a cause for concern but when it becomes prolonged that is when it is.

Research has shown that as men get older the more likely they will develop some form of erectile dysfunction.

In a study published in the Annals of Internal Medicine (2003), it was shown that erectile dysfunction had a greater occurrence amongst older men and sexual functioning fell drastically after the age of fifty.

Doctors had long thought that the problem stemmed from psychological factors but recent information and evidence, has shown than for close to 90% of all cases physical factors were the underlying cause in men fifty years old and over.

Research of men (53-90 years old) has also shown that when things like age, activity level, smoking and alcohol consumption are taken together, older men reported a higher incidence of erectile dysfunction and that most of the younger men (close to 74%) had very good sexual functioning.

In the same study about 10% of the men over eighty did not report a significant problem with sexual functioning and some 12% of younger men had serious problems sexually.

It has also been found that close to 30% of men over fifty had severe sexual dysfunction.

Similar results were seen in the Massachusetts Male Aging Study (1994) which found that some 52% of respondents had some form of erectile dysfunction and 10% had complete erectile dysfunction.

This survey was of men forty to seventy years old. These results was supported by The National Health and Social Life Survey of men (18-59 years old) which found that just over 10% of had complete erectile dysfunction.

It has also found that the rate of moderate erectile dysfunction has increased to close to 34%. On a global scale similar results have been found with similar rates of occurrence.

These results have all shown that the average age for erectile dysfunction would be hard to define although some surveys put it at between 59-69 years of age.

This difficulty in defining an average age is due to the fact that the problem affects men of all ages and as the population ages and other risk factors come into play the average age will vary and change often depending on the person's lifestyle.

Things like diabetes, heart disease, hypertension, and urinary tract infections all contribute to erectile dysfunction in one way or the other. For men who have a healthy lifestyle without any form of chronic disease, they are not at such great risk of having erectile dysfunction.