A man with impotence has either a problem getting an erection or difficulty maintaining one. This usually interferes with sexual activity.
Impotence can happen suddenly or gradually. Some men slowly lose the firmness of their erections or how long the erections last.
In other men, especially those whose impotence is largely caused by psychological factors, the problem may occur unpredictably. It can improve at any time.
Men with impotence may continue to have normal orgasm and ejaculation without a full erection.