We need to distinguish between primary and secondary impotence.
Primary impotence means that a man never had an erection.
Organic causes may be responsible for this, and an examination by a urologist is indicated. Secondary erectile difficulties means that a man may have an erection at certain times, but not at other times, in certain situations only or with certain partners only. We will discuss secondary erectile difficulties here. Research indicates that half of the male population will experience occasional transient episodes of impotence within the limits of healthy sexual behavior. Multiple factors may cause erectile difficulties.