Erectile dysfunction is defined as the inability to develop and maintain an erection for satisfactory sexual intercourse or activity. It is considered to be a separate concern from premature ejaculation. There is no universally agreed upon criteria for how consistent the problem has to be and for what duration it needs to be present to fulfill the definition, although three months is often used as a guideline.

In most studies erectile dysfunction will be defined based on a subjects response to a question related to their own perception of their erections (not the reports of partners).

In large part the result of new medications to treat erectile dysfunction, there has been a surge in research on erectile dysfunction. Recent studies have suggested that the prevalence of erectile dysfunction is as high as 1 in 5 men.

ED, impotence, erectile difficulties