If the penis under men is always prone to erection, there are several reasons:
First, the cause of physiological, men in young people, due to the high level of sex hormones in the body, and the surrounding tissue of the penis or penis are slightly stimulated by the outside world, it will cause penis erections, or often watch yellow novels, images, and videos often watching yellow novels, images, and videos. Wait, this stimulus signal is passed to the penis nerve, which will also cause penile erection. With age, this erection will gradually decrease.
Second, hyperthyroidism refers to the sexual desire of men, exceeding normal state, frequent sexual excitement, increasing frequency of sexual life, and at the same time cannot be controlled by themselves. Two cases.