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Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Jerry R. Balentine, DO, FACEP

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

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Erectile dysfunction (ED) is a man's inability to achieve and maintain an erection of the penis. While not a disease in itself, is may be a symptom of other diseases. Erectile dysfunction and impotence are frequently used interchangeably in the lay and medical literature, but impotence can also mean incapable of sexual intercourse and sterile (infertile). However, erectile dysfunction often can be intermittent; because some men occasionally have erectile dysfunction and other times are capable of intercourse with normal semen production, they do not fit into all of the implied meanings of impotence. For example, men that have "premature ejaculation" (defined as ejecting semen from the penis, usually with orgasm sooner than the man or his partner wishes during sexual activity) are considered to have a form of erectile dysfunction. Consequently, not all men with erectile dysfunction symptoms are "impotent" although they may be "impotent" intermittently when attempting any form of intercourse.

As many as 50% of all men (ages 40–70 and older) experience a form of erectile dysfunction at some time during their lifetime, with the incidence increasing as the man ages. These statistics on erectile dysfunction vary in the literature, but it is clear that erectile dysfunction is common. Many clinicians prefer to simply classify erectile dysfunction in general terms of mild, moderate, or severe. Until recently, the large majority of men with erectile dysfunction have never discussed this with their doctors. However, men consider this as an important aspect of their lives and their sexual partner's life, and even a single incidence of erectile dysfunction may cause excessive concerns with the man and his partner. Although many men still are reluctant to discuss erectile dysfunction with anyone, current medical and lay press articles, constant TV and internet saturation of commercials, and programs about erectile dysfunction and its treatment(s) have decreased some men's inhibitions about discussing erectile dysfunction.

To better understand erectile dysfunction, it is important to understand how an erection develops. An erection occurs when sexual stimulation occurs due to mental or physical stimulation (or both) that cause, via nerve impulses, spongy tissue in the penis (corpora cavernosa) to expand when smooth muscle (about one-half of the corpora cavernosa tissue) in the penis relaxes (via nitric oxide - cyclic GMP production) and allows the spongy tissue to become saturated with blood under pressure (about 200mm Hg pressure). An erection is sustained when the veins in the tunica albuginea that drain the corpora cavernosa are compressed by this spongy tissue. The erection ceases when the smooth muscle contracts (due to falling cyclic GMP production), and allows the blood to drain through the veins in the tunica albuginea. An erection is the result of a complicated biological response to sexual stimulus that involves mental perception, physical (or tactile) sensation, and chemical responses to these nerve-generated impulses in a man over time that usually peak and begin to cease or reverse after ejaculation. Erectile dysfunction can result when one or more of these complicated steps are not completed. Unfortunately, individual men often have many different causes for erectile dysfunction, but diagnosis of an man's erectile dysfunction almost always centers on one or more of these problems:

• Mental health
• Nerve system function (both central and peripheral)
• Physical health (especially the vascular system)
• Chemical changes in the body (especially hormonal and nerve-generated chemical changes)

There are multiple ways to begin to determine the underlying problems that result in erectile dysfunction; all of them begin with a detailed sexual history. Again, the car analogy; if your car is not performing well, would you not answer the mechanic's pointed questions about its function? In addition, if you answered the questions and the mechanic said you better go to see the specialist at the dealer's to get the best answers, and any needed "parts and fine tuning," what would you do? The same is similar for men with erectile dysfunction; while their primary doctor may help diagnose and treat some men with erectile dysfunction, men often may benefit from a specialist (such as an urologist, endocrinologist, or psychologist) that diagnoses and treats specific aspects of erectile dysfunction. Some doctors will ask the patient to complete a standardized test before they interview the them in depth. An example of a short test is below.

The International Index of Erectile Function (IIEF) has developed a short format of five questions that are graded from 0-5 by the man with a potential erectile dysfunction problem. A score of 5 is the best rating. The five questions are as follows:

1. How do you rate your confidence that you could achieve and maintain an erection?
2. When you had erections with sexual stimulation, how often were your erections hard enough for penetration?
3. During sexual intercourse, how often were you able to maintain your erection after you had penetrated your partner?
4. During sexual intercourse, how difficult was it to maintain your erection to the completion of intercourse?
5. When you attempted sexual intercourse, how often was it satisfactory for you?

The score for no erectile dysfunction problems is 25, while a score of 11 usually indicates moderate to severe erectile dysfunction. However, this set of questions only begins to explore the erectile dysfunction problem and does not reveal underlying causes of erectile dysfunction.

Treatment of erectile dysfunction varies with the underlying causes. Some of the treatments for ED are outlined below.

• Oral medications that enhance the nitric oxide – cyclic AMP, and relaxes smooth muscle in the penis such as sildenafil (Viagra), Tadalafil (Cialis) and Vardenafil (Levitra) and others. These medications can be dangerous to use in some men taking nitrates, high blood pressure medications, anticoagulants, and some prostate medications or have diseases such as diabetes, heart disease, stroke, and blood pressure problems.
• Other medications such as alprostadil self-injection (into the penis base), alprostadil penis suppository, and hormone (testosterone) therapy may be needed.
• Vacuum constriction device (penis pump) is a tube placed over the penis and then a vacuum is made by removing the air in the tube which then pulls blood into the penis, producing an erect penis. A tension ring (constricting ring) is then slipped around the penis base. The ring holds the blood in the penis and maintains the erection after the tube is removed. The ring is removed after intercourse.
• Penile implants are surgically inserted devices into the penis that are either mechanically inflatable or are semi-rigid rods. This surgery is done only by urologic specialists, and is usually the last treatment tried on men with severe erectile dysfunction.
• Blood vessel surgery is sometimes attempted on men with damaged penile blood vessels
• Psychological counseling and co-counseling with the sex partner of men with erectile dysfunction may be successful without medical or surgical treatment with some men; counseling may help in conjunction with the other treatments for erectile dysfunction.

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