A lot of the time, the issue is a combination of both. For instance, cortisol – which is an important steroid hormone in the body – is released in greater amounts when we're stressed. It's supposed to briefly shut down non-essential functions like reproduction and fighting off illnesses whilst you deal with the danger at hand. However, the chronic and ongoing stress of modern life increases our background cortisol levels, activating the sympathetic system and stopping an erection.
Your erection problems may be putting a strain on your relationship. You may have stopped touching and cuddling your partner, scared that it could lead to sex - and then to disappointment because you cannot get hard. You may have found it has led to regular arguments. At its worst, erection problems can lead to the breakdown of relationships. So it is vitally important to talk things over with your partner.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Additionally, the physiologic processes involving erections begin at the genetic level. Certain genes become activated at critical times to produce proteins vital to sustaining this pathway. Some researchers have focused on identifying particular genes that place men at risk for ED. At present, these studies are limited to animal models, and little success has been reported to date.  Nevertheless, this research has given rise to many new treatment targets and a better understanding of the entire process.
Your question reminds me of this brilliant Louis CK bit from his special Hilarious, in which he talks about a guy who said his appetizer was amazing. "Really? You were amazed by a basket of chicken wings? What if Jesus comes down from the sky and makes love to you all night long and leaves the new living lord in your belly? What are you going to call that? You used amazing on a basket of chicken wings! You've limited yourself verbally to a shit life."
Alprostadil may also be administered into the urethral opening of the penis. In MUSE (medical urethral system for erection), the man inserts a thin tube the width of a vermicelli noodle into his urethral opening and presses down on a plunger to deliver a tiny pellet containing alprostadil into his penis. The drug takes about 10 minutes to work and the erection lasts about an hour. The main side effect is a sensation of pain and burning in the urethra, which can last about five to 15 minutes.