Frequently asked questions about erectile dysfunction

What is erectile dysfunction?

Erectile dysfunction, sometimes called ED or impotence, is the repeated inability to get or keep an erection firm enough for sexual intercourse. The word "impotence" may also be used to describe other problems that interfere with sexual intercourse and reproduction, such as lack of sexual desire and problems with ejaculation or orgasm. Using the term erectile dysfunction makes it clear that those other problems are not involved.

Erectile dysfunction can be a total inability to achieve erection, an inconsistent ability to do so, or a tendency to sustain only brief erections. These variations make defining ED and estimating its incidence difficult. According to NHS Choices, ED is an extremely common condition in the UK, with an estimated half of all men between the ages of 40 and 70 experiencing ED at least once. Studies in America show that the rate of ED related visits to the doctor tripled between 1985 and 1999. This increase happened gradually, presumably as treatments such as vacuum devices and injectable drugs became more widely available and discussing erectile function became more accepted. Perhaps the most publicised advance has been the bringing in of the oral drug sildenafil citrate, introduced in 1998.

In older men, ED usually has a physical cause, such as disease, injury, or side effects of medications. Any disorder that causes injury to the nerves or impairs blood flow in the penis has the potential to cause ED. Incidence increases with age with about seven in ten men aged 70 or over having ED. However, it is not an inevitable part of ageing.

ED is treatable at any age, and awareness of this fact has been growing. More men have been seeking help and returning to normal sexual activity because of improved, successful treatments for ED.

How does an erection occur?

First, here is some background information on erections. The penis contains two chambers, called the corpora cavernosa, which run the length of the organ. A spongy tissue fills the chambers. The corpora cavernosa are surrounded by a membrane, called the tunica albuginea. The spongy tissue contains smooth muscles, fibrous tissues, spaces, veins, and arteries. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa and is surrounded by the corpus spongiosum.

Erection begins with sensory or mental stimulation, or both. Impulses from the brain and local nerves cause the muscles of the corpora cavernosa to relax, allowing blood to flow in and fill the spaces. The blood creates pressure in the corpora cavernosa, making the penis expand. The tunica albuginea helps trap the blood in the corpora cavernosa, thereby sustaining erection. When muscles in the penis contract to stop the inflow of blood and open outflow channels, erection is reversed.