Well, men go through the exact same anxieties, but the difference between men and women is the result is far more obvious in men. The first thing you need to do when you suspect your man is suffering from anxiety-induced erectile dysfunction is to look at him while you're going down on him and say this: "Is there anything you'd really like me to do? I'm willing to do whatever turns you on."
Diabetes is one of the most common causes of ED. Chronically high blood sugar levels can result in nerve damage that affects your body’s ability to translate pleasurable sexual stimulation into an erection. Diabetes can also lead to issues with circulation, which reduces blood flow to the penis and makes it more difficult to keep an erection that is hard enough for intercourse.
Another study compared the response of surgically and medically castrated rabbits to vardenafil with that of control rabbits.  Castrated rabbits did not respond to vardenafil, whereas noncastrated rabbits did respond appropriately. This result suggests that a minimum amount of testosterone is necessary for PDE5 inhibitors to produce an erection.