Erectile dysfunction is when you cannot get or keep an erection firm enough to have sex. You may have ED if you - can get an erection sometimes, though not every time - can get an erection, yet it does not last long enough for sex - are unable to get an erection at all ED is sometimes called impotence; however, doctors use this term less often now. See the Pronunciation Guide for tips on how to say the words in bold type. 
What is (are) What I need to know about Erectile Dysfunction ?