Penile erection; an indispensable phenomenon for reproduction and/or the sexlife of almost every man. However, the man whose nights of sleep get frequently disrupted due to painful nocturnal erections, the so called “sleep-related painful erections”, might prefer never to have an erection again. Remarkably, the erotic erections remain undisturbed. Nevertheless, a (sexual) realtionship can be seriously disturbed by the consequences of the sleep deprivation: stress, anxiety, absenteeism and feelings of despair. Only a single prolonged erection, that lasts beyond 4 hours and is called “priapism”, can even cause the penile corporal tissue to become completely necrotic and irreversibly devastated.This thesis describes the historical aspects, sym...