Male impotence. Abstract artwork depicting male impotence, showing a male torso and a male symbol representing the lack of penile erection. Impotence is the inability in men to achieve or maintain an erection. As the most common male sexual disorder, it affects most men at some stage. Impotence may be caused by psychological factors (stress, fatigue, anxiety) or a physical disorder such as diabetes or injury. It is more common as men get older. Treatments of impotence depend on the cause but include sex therapy, penile implants, and the impotence drug Viagra.