The symptoms

Erectile dysfunction is the constant inability to maintain or develop an erection sufficient to have sexual intercourse or a satisfyng penetration; therefore, it is very important to distinguish between the occasional loss of erection or the occasional inability to develop an erection, and the persistent inability to develop an erection. The occasional or episodic loss is not considered an erectile dysfunction. Every man can experience it and it can be due to different factors, such as tiredness, alcohol or other substances, the lack of a suitable place where to have sex, and so on. The males who experience some of these factors during time are not likely to develop erectile dysfunction. Erectile dysfunction itself appears on longer time spans. However, this problem can have both an organic and a psychological cause. The symptoms are different:
Erectile dysfunction has a psychological origin when the male experiences spontaneous erections. That is, when he accidentally develops an erection, for example at nighttime or in the morning.
When erectile dysfunction has an organic origin, that is, when there is a physical or physiological cause to the problem, the man does not experience this sort of erections. Another symptom that might indicate that the dysfunction has a psychological origin is that the erections developed while masturbating are much stronger than the ones developed during sexual intercourse. The same can be said if the problem does not occur with every partner or with every sexual practice.