A rigid or nearly rigid erectile response to intracavernous injection of pharmacologic test doses of a vasodilating agent (see below) indicates adequate arterial and veno-occlusive function. This suggests that the patient may be a suitable candidate for a trial of penile injection therapy. Genital stimulation may be of use in increasing the erectile response in this setting. This diagnostic technique also may be used to differentiate a vascular from a primarily neuropathic or psychogenic etiology. Patients who have an inadequate response to intracavernous pharmacologic injection may be candidates for further vascular testing. It should be recognized, however, that failure to respond adequately may not indicate vascular insufficiency but can be caused by patient anxiety or discomfort. The number of patients who may benefit from more extensive vascular testing is small, but includes young men with a history of significant perineal or pelvic trauma, who may have anatomic arterial blockage (either alone or with neurologic deficit) to account for erectile dysfunction.
The primary nerve fibers to the penis are from the dorsal nerve of the penis, a branch of the pudendal nerve. The cavernosal nerves are a part of the autonomic nervous system and incorporate both sympathetic and parasympathetic fibers. They travel posterolaterally along the prostate and enter the corpora cavernosa and corpus spongiosum to regulate blood flow during erection and detumescence. The dorsal somatic nerves are also branches of the pudendal nerves. They are primarily responsible for penile sensation. 
Because there's no word better than "love," where do you go from "I love you"? I really, really love you? I love you so much? With a cherry on top? Ugh. Pretty soon, you're in Hallmark territory, quoting bad pop lyrics. Since "I love you" is as good as it gets, maybe you feel you've peaked. You might be wondering: Is this it? Do you just say the same thing, over and over, for the rest of your days? "I love you" can be scary when it seems to be a plateau and the end of something. But that's bullshit. Hopefully, "I love you" is just the beginning.
Erectile dysfunction can have so many long-lasting effects that the inability to achieve an erection is almost the least of them. Men who suffer from erectile dysfunction often suffer from self-esteem concerns, and these can then translate into issues regarding sexual relationships, friendships, and even work-related relationships. As things begin to spiral out of control, men dealing with erectile dysfunction may go on to suffer from depression, anxiety, and other psychological problems that further inhibit relationship and sexual intimacy. So what is it that’s causing this mess?
ED may occur with or without other sexual dysfunction, including decreased libido (decreased interest in sexual activity), orgasmic dysfunction (troubles achieving an orgasm/climax), and ejaculatory dysfunction (problems with the fluid released during sex, including lack of ejaculation [anejaculation], small volume ejaculate, ejaculation that occurs too quickly [premature ejaculation], ejaculate that goes backward into the bladder [retrograde ejaculation] and pain with ejaculation).
Currently, there are no therapies that cure erectile dysfunction. However, a number of effective therapies are available that allow an individual to have an erection when desired. Depending on the cause of the erectile dysfunction, certain therapies may be more effective than others. Although there is limited data on lifestyle modification, intuitively, decreasing risk factors for erectile dysfunction may help prevent progression of disease.