Simplify the following text for a Grade 9 native English-speaking person.
Original: Erectile dysfunction ( also known as ED or '' ( male ) impotence '' ) is a sexual dysfunction characterized by the inability to develop and\/or maintain an erection .
Simplified: A man who often has problems having or keeping an erection of his penis is said to have erectile dysfunction . Erectile dysfunction is also known as ED , impotence or male impotence .