The pathogenesis of organic ED is related to dysfunction of the endothelium. Endothelial cells can become injured through a variety of mechanisms, most of which cause oxidative stress on the tissues. Many of these causes of oxidative stress are related to lifestyle issues which lead to hypertension, diabetes and dyslipidaemia (figure 1). Endothelial cell dysfunction results in reduction of endothelium-dependent vasorelaxation as well as increased adhesion of leukocytes to the endothelium. Endothelial cell injury then leads to a variety of sequelae, including ED, other types of vasoconstriction, atherosclerosis and thrombus formation.18
In terms of practical solutions, this is a common problem so there are some common aids. Drugs like Viagra or Cialis or Levitra work for many, many men. If his doctor recommends it, there’s no shame in popping a pill if it solves the problem — particularly if it helps alleviate the anxiety. Sometimes, a guy just needs to get his groove back for a while so he can relax and start having fun again. Also don’t forget the noble, oft-ignored cock ring, which constricts blood flow and helps men keep it up. They’re cheap and easy.
Associated morbidity may include various other male sexual dysfunctions, such as premature (early) ejaculation and male hypoactive sexual desire disorder. The NHSLS found that 28.5% of men aged 18-59 years reported premature ejaculation, and 15.8% lacked sexual interest during the past year. An additional 17% reported anxiety about sexual performance, and 8.1% had a lack of pleasure in sex. 
Me and my boyfriend have been together almost two years, and he has only said "I love you" about a dozen times. I know he loves me by his actions but I would still like to hear the words. I have tried talking to him about it but he also isn't one for talking about anything that could possibly be uncomfortable. Sometimes this really makes me insecure, especially since I tell him daily I love him. Other times I feel like I am just being silly and that actions speak louder than words. What should I do?
You're not hard. You're about to have sex for the first time with your date, who's truly beautiful. All you want to do is present your glorious, super strong erection and let it do the talking. And yet when you look down, you're limp instead of hard. This doesn't make any sense! you think. Every element you could possibly need for an erection is here. Nudity, beauty, passion, the tantalizing thrill of boning someone for the first time, and a little bit of booze to take the edge off. What on earth is wrong and why are you so unlucky? You turn to your date. "I swear, this never happens..."
The mood is set, the wine is drunk, and you’re ready to go. Only one problem, despite wanting to have sex, your penis doesn’t seem quite up to the task. Trouble keeping an erection is often depicted as a problem for older men, but factors other than age can affect a man’s ability to have and keep an erection. Here are 6 reasons why you or your partner may have trouble with their erections.
The most important organic causes of impotence are cardiovascular disease and diabetes, neurological problems (for example, trauma from prostatectomy surgery), hormonal insufficiencies (hypogonadism) and drug side effects. Psychological impotence is where erection or penetration fails due to thoughts or feelings (psychological reasons) rather than physical impossibility; this is somewhat less frequent but can often be helped. In psychological impotence, there is a strong response to placebo treatment.
Qaseem, A., Snow, V., Denberg, T. D., Casey, D. E., Forciea, M. A., Owens, D. K., & Shekelle, P. (2009). Hormonal testing and pharmacologic treatment of erectile dysfunction: A clinical practice guideline from the American College of Physicians. Annals of internal medicine, 151(9), 639-649. Retrieved from http://annals.org/aim/article/745155/hormonal-testing-pharmacologic-treatment-erectile-dysfunction-clinical-practice-guideline-from