Erectile dysfunction, or ED, is when it is hard to get or keep an erection that's firm enough for sex. ED affects as many as 30 million men.
Most men have problems with erections from time to time. But when this happens more than half of the time, then ED is present. ED can happen when health problems limit blood flow or damage nerves in the penis. ED can also be caused by stress or emotional reasons. ED can be an early warning of a more serious illness. Heart disease, high blood pressure and high blood sugar can all cause ED. Finding and treating the cause(s) of your ED can help your overall health and well-being.
How Erections Work
When you are not sexually aroused, your penis is soft and limp. During sexual arousal, nerve messages release chemicals that increase blood flow into the penis. The blood flows into 2 erection chambers made of spongy tissue (the corpus cavernosum) in the penis. The "smooth muscle" in the erection chambers relaxes, which lets blood enter and stay in the chambers. The pressure of the blood in the chambers makes the penis firm, giving you an erection. After you have an orgasm, the blood flows out of the chambers and the erection goes away.