IMPOTENCE

Inability to achieve or maintain erection of the penis ; hence, inability to participate fully in sexual intercourse .

Erectile impotence (failure to achieve erection) may have either physical causes (e.g., alcoholism, endocrine disease) or psychological ones (e.g., anxiety, hostility toward the partner). Ejaculatory impotence (inability to reach orgasm, sometimes with an erection maintained for a long time) nearly always has an emotional cause. See also Viagra .