Erectile Dysfunction Overview
On this page:- Introduction
- How does an erection occur?
- What causes ED?
- How is ED diagnosed?
- How is ED treated?
- Hope Through Research
- Points to Remember
- For More Information
Introduction
Erectile dysfunction, sometimes called “impotence,” is the inability to get or keep an erection firm enough for sexual intercourse. The word “impotence” may also be used to describe difficulty in obtaining or maintaining an erection. Other problems can interfere with sexual intercourse and reproduction, such as lack of sexual desire and problems with premature or delayed ejaculation, or inability to have an orgasm. These other conditions are different problems than erectile dysfunction, and have different causes and solutions.
Erectile dysfunction, or ED, 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. It is estimated that 15 million to 30 million American men have some degree of ED. The good news for men is that ED is treatable, and almost all men can be helped to have a satisfying sexual relationship if they are motivated to try several different solutions until they find the one that works best for them.
In most men ED has a physical cause, such as medical diseases, injury, or side effects of drugs. Any disorder that causes injury to the nerves or impairs blood flow in the penis has the potential to cause ED. It has also been determined that approxiamtely 40% of men with ED also have heart disease, which may be silent, so men with ED should be evaluated by their medical doctor for heart problems.
The incidence of ED increases with age: about 5 percent of 40-year-old men and between 15 and 25 percent of 65-year-old men experience ED. But ED is not an inevitable part of aging, and lifestyle choices can affect the chances of getting ED. A lifestyle that maintains a healthy heart is also good for maintaining good erections, including weight loss, control of blood pressure, diabetes, and cholesterol, limiting alcohol, and quitting smoking. In addition, regular sexual activity throughout a man’s life may help to maintain good erections.
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. Urologists are doctors who specialize in problems of the urinary tract and men’s health, and are the best experts to treat men with ED.
How does an erection occur?
Small arteries from deep inside the pelvis bring blood to the penis; the arteries are mostly closed when a man does not have an erection but open to bring blood to the penis during an erection. The penis contains two chambers called the corpora cavernosa, which run the length of the organ (see figure 1). A spongy tissue that fills with blood during an erection fills the chambers. The corpora cavernosa are surrounded by a tough but elastic covering, called the tunica albuginea. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa on the bottom of the penis.
Arteries (top) and veins (bottom) penetrate the long, filled cavities running the length of the penis—the corpora cavernosa and the corpus spongiosum. Erection occurs when relaxed muscles allow the corpora cavernosa to fill with excess blood fed by the arteries, while drainage of blood through the veins is blocked.
Erection begins with sensory or mental stimulation, or both. Impulses from the brain and local nerves cause the muscles in the arteries supplying 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 until it reaches the limit of its expansion. The expanded spongy tissue in the penis compresses the outflow veins against the inside of the tunica albuginea, trapping the blood in the corpora cavernosa and sustaining the erection. When muscles in the arteries supplying blood to the penis contract to stop the inflow of blood, the pressure in the penis decreases. opening the outflow channels, and the erection subsides.
What causes ED?
An erection requires a number of body systems to work properly together. The process of obtaining an erection requires the right psychological state of mind, proper levels of male hormones in the body, proper function of the nervous system including the brain, spinal cord and peripheral nerves, adequate blood flow to the penis, and proper function of the penile veins to trap blood in the penis. Problems with any of these systems can cause erectile dysfunction.
Psychological conditions such as stress, relationship problems, or depression can affect sexual function. Some men can have psychological ED with no problems in the nervous or blood vessel systems. This is more common in men under age 40, and with this condition men may find that they have normal erections on some occasions and poor erections on others, and usually have normal erections at night while they are asleep or when they wake in the morning. When men have anxiety about their sexual performance it can make it very difficult to get an erection, a condition called “performance anxiety.” Many men with early ED from other causes can have performance anxiety that makes their physical erection problem worse.
Proper sexual function requires normal levels of the male hormone testosterone. Testosterone plays a major role in the psychological interest in sex, called libido, and men with low testosterone usually have low libido. Low testosterone can also affect the ability to achieve and maintain an erection. Only about 5-10% of men with ED have low testosterone, but it is easily tested for and treated.
Normal function in the nervous system, from the arousal center in the brain to the blood vessels in the penis, is necessary for proper erections. Damage to nerves from spinal cord injury, herniated disks, or from major pelvic surgery for prostate and bladder cancer can cause ED. In addition, diabetes causes damage to nerves as well as blood vessels and is a major cause of ED.
Because erections are caused by blood flow into the penis they can be affected by any condition that affects the health of men’s vascular system. These other medical conditions include heart disease, high blood pressure or cholesterol, atherosclerosis, diabetes, smoking, obesity, and kidney failure. The most common cause of ED is venous leak, which means that the penis cannot trap the blood in the penis and so it cannot maintain rigidity. The most common causes include advanced age, smoking, and high blood pressure. Other men have ED because they cannot pump enough blood into the penis because the arteries are blocked. The same things that cause blocked arteries in the heart can block blood flow to the penis, including smoking, high blood pressure, diabestes, and elevated cholesterol. Between 35 and 50 percent of men with diabetes experience ED, making it one of the most common causes.
Injury to the penis, spinal cord, prostate, bladder, and pelvis can lead to ED by harming nerves, smooth muscles, arteries, and fibrous tissues of the corpora cavernosa. In addition, many common medicines—blood pressure drugs, anti-histamines, anti-depressants, tranquilizers, appetite suppressants, and cimetidine (an ulcer drug)—can produce ED as a side effect.
How is ED diagnosed?
Medical and sexual histories help define the degree and nature of ED. Decreased sex drive, called libido, can indicate a low testoseterone level. A medical history can disclose diseases that lead to ED, while a simple recounting of sexual activity might distinguish among problems with sexual desire, erection, ejaculation, or orgasm.
The use of certain prescription or illegal drugs, particularly drugs for high blood pressure, can be a cause of ED, and drug effects may contribute to ED in up to 25 percent of ED cases. A change in medications can often alleviate the problem, but this should only be done in conjunction with a patient’s primary care doctor.
Physical Examination
A physical examination can give clues to systemic problems. For example, if the penis has decreased sensitivity to light touch, a problem in the nervous system may be the cause. Abnormal secondary sex characteristics, such as hair pattern or breast enlargement, can point to hormonal problems. The examiner might discover a circulatory problem by observing decreased pulses in the wrist or ankles. Unusual characteristics of the penis itself could suggest the source of the problem—for example, a penis that bends or curves when erect could be the result of Peyronie’s disease.
Laboratory Tests
Several laboratory tests can help diagnose ED. Tests for systemic diseases include blood counts, urinalysis, lipid profile, and measurements of creatinine and liver enzymes. Measuring the amount of free testosterone in the blood can yield information about problems with the endocrine system and is indicated especially in patients with decreased sexual desire.
Penile Doppler Testing
The best test to determine the condition of the blood vessels in the penis is called a penile doppler test. This test measures the blood flow into and out of the penis during erection. The test is done in the office and uses injection of a medication into the penis to produce an erection. A doppler ultrasound device is placed on the penis to measure the blood vessels.
Other Tests
Monitoring erections that occur during sleep (nocturnal penile tumescence) can help rule out certain psychological causes of ED. Healthy men have involuntary erections during sleep. If nocturnal erections do not occur, then ED is likely to have a physical rather than psychological cause. Tests of nocturnal erections are not completely reliable, however.
Psychosocial Examination
A psychosocial examination by a psychologist who specializes in treating men, women, and couples with sexual dysfunction can reveal psychological issues contributing to ED. A man’s sexual partner may also be interviewed to determine expectations and perceptions during sexual intercourse.
How is ED treated?
Most physicians suggest that treatments start with lifestyle changes to improve a man’s overall health. Eliminating cigarette or marijuana smoking or high alcohol consumption are the first steps that men should take. Men should also reconsider all of the drugs that they are taking to see if any could be causing ED. Control of high blood pressure is very improtant for health of your heart, kidneys, and erections, and it is uncommon in our experience to see a major difference in ED by changing high blood pressure medications. If you think that ED started or was worsened when a particular drug was started, you should discuss this with your primary care doctor and ask whether you can try a different class of blood pressure medicine.
Psychological counseling with a therapist who specializes in sexual problems can help many patients, especially those who have a psychological cause of ED, who are depressed, or who have other issues related to their sexuality. It is a very helpful treatment to use alongside other treatments for ED. Since most men with ED have a medical cause of the problem, treatment of the ED with one of the treatments described below is usually necessary to restore a man’s ability to have intercourse. Most men prefer to start treatment with a trial of one of the oral medications, and 2/3 of men will get improvement in their ED. Other options include penile injection therapy, vacuum devices, and surgically implanted devices.
Drug Therapy
(Also see “Getting the most out of ED medications“)Oral medications for ED are usually the first step that most men take when they decide that they are not satisfied with their sexual function. In many cases the primary care physician will prescribe one of these medications before the patient is sent to the urologist. There are now three medications which are effective treatments for ED: sildenifil (Viagra), vardenifil (Levitra), and tadalafil (Cialis).
Viagra, Levitra, and Cialis work by enhancing a man’s natural erection mechanism. These medications improve the rigidity of a man’s erection in roughly 2/3 of men, but the medications do not give a man erection if he is not sexually aroused. The medications are taken 30-60 minutes before a man desires to have intercourse, and the improvement in the erection system lasts 4-6 hours for Viagra and Levitra, and up to 36 hours with Cialis.
The recommended starting dose for Viagra is 50 mg, and the physician may adjust this dose to 100 mg or 25 mg, depending on the patient. The recommended starting dose for Levitra and Cialis is 10 mg, and the physician may adjust this dose to 20 mg if 10 mg is insufficient.
Neither Viagra or Levitra should be used more than once a day, and Cialis usually is not used more than every other day. Men who take nitrate-based drugs such as nitroglycerin for heart problems should not use either drug because the combination can cause a sudden drop in blood pressure. Also, these drugs should be taken with caution with any of the drugs called alpha-blockers, which are used to treat prostate enlargement or high blood pressure. Cialis can be taken with the alpha-blockers Flomax and Uroxatral, but men with prostate enlargement should strongly consider a minimally-invasive prostate treatment before they start these medications
Men who have documented low testosterone can be treated with testosterone cream or gel which is applied to the skin daily, with daily testosterone patches, or with injections in the office every 2-4 weeks. Oral testosterone can reduce ED in some men with low levels of natural testosterone, but it is often ineffective and may cause liver damage. Patients also have claimed that other oral drugs—including yohimbine hydrochloride, dopamine and serotonin agonists, and trazodone—are effective, but the results of scientific studies to substantiate these claims have shown that they are no more effective than placebo. There are no known herbal products that improve sexual function in the way that these medications do.
Surgery
(see also “Penile Implant Surgery“)Implanted devices, known as penile prostheses, can restore erections in many men with ED. Most men try less invasive approaches before they have implant surgery, but more than 80% of men who have surgery are very satisfied with the results. Once a penile implant is in place men can have intercourse whenever they want with confidence that they will be successful. Many men don’t realize until after penile implant surgery that they had been avoiding sexual relations because they feared that they would be unsuccessful. After implant surgery men are confident that they will be able to have intercourse successfully whenever they wish to. There are two main types of penile implants, malleable (also called semi-rigid) and inflatable.
With an inflatable implant, erection is produced by squeezing a small pump implanted in a scrotum. The pump causes fluid to flow from a reservoir residing in the lower pelvis to two cylinders residing in the penis. The cylinders expand to create the erection.
Inflatable implants consist of paired cylinders, which are surgically inserted inside the penis and can be expanded using pressurized fluid (see figure above). Tubes connect the cylinders to a fluid reservoir and a pump, which are also surgically implanted. The patient inflates the cylinders by pressing on the small pump, located under the skin in the scrotum. Inflatable implants can expand the length and width of the penis somewhat. They also leave the penis in a more natural state when not inflated. Dr. Rosen trained with the the inventor of the inflatable penile prosthesis, and are very experienced in this type of surgery. We recommend implantation of prostheses from Mentor Corporation or American Medical Systems.
Malleable implants consist of paired rods, which are inserted surgically into the corpora cavernosa. The user manually adjusts the position of the penis and, therefore the rods, by bending the penis straight to have intercourse and down when dressed. Adjustment does not affect the width or length of the penis. This type of implant has no moving parts so it is very reliable, but it does not provide as realistic an erection as the inflatable penile implant.
Surgery to repair arteries can reduce ED caused by obstructions that block the flow of blood. The best candidates for this surgery are young men (less than 40) with discrete blockage of an artery because of an injury or fracture of the pelvis, usually from a motor vehicle accident. The procedure is almost never successful in older men with widespread blockage.
Surgery to veins that allow blood to leave the penis usually involves an opposite procedure—intentional blockage. Blocking off veins (ligation) can reduce the leakage of blood that diminishes the rigidity of the penis during erection. However, only about 50% of men get intial improvement and the long term effectiveness is low, and this type of surgery is rarely done.
Penile Injection Therapy
(see also “Penile Injection Therapy“)Many men achieve stronger erections by injecting drugs into the penis, causing it to become engorged with blood. Men inject the medication into the penis when they want to have an erection and within 10 minutes can have a fully rigid erection that lasts for 30-60 minutes (figure 3). The needles used for injection are tiny and most men don’t feel any more discomfort than a pin prick. These drugs may create unwanted side effects, however, including persistent erection (known as priapism) and scarring.
Injection of a medication into the penis can cause a good erection in 75% of men.
Intraurethral medication
A system for inserting a pellet of alprostadil into the opening of the urethra at the end of is marketed as Muse. The system uses a prefilled plastic applicator to deliver the pellet about an inch into the urethra. The medication is absorbed into the penis through the urethra, and an erection will begin within 8 to 10 minutes and may last 30 to 60 minutes. Unfortunately only about 15% of men will get a satisfactory erection with this medication. The most common side effects are aching in the penis, testicles, and area between the penis and rectum; warmth or burning sensation in the urethra; redness from increased blood flow to the penis; and minor urethral bleeding or spotting.
Vacuum Erection Devices
(see also “Vacuum Erection Device video“)Mechanical vacuum erection devices create erection by creating a partial vacuum which draws blood into the penis, engorging and expanding it. The system has three components: a plastic cylinder which is slipped over the penis, a built-in pump, which draws air out of the cylinder; and an elastic band, which is placed around the base of the penis to maintain the erection after the cylinder is removed (see figure 4). This type of treatment has been around since the late 1960s, and many men are very satisfied with it. Some men find that the vacuum and constricting band are uncomfortable, and others feel that the procedure lacks the spontaneity of other treatments. This treatment is covered by Medicare, and men who interested can meet with a representative from the manufacturer and try the device before they purchase it.
A vacuum-constrictor device causes an erection by creating a partial vacuum around the penis, which draws blood into the corpora cavernosa. Pictured here are the necessary components: (a) a plastic cylinder, which covers the penis; (b) a pump, which draws air out of the cylinder; and (c) an elastic ring, which, when fitted over the base of the penis, traps the blood and sustains the erection after the cylinder is removed.
Psychotherapy
Experts often treat psychologically-based ED using techniques that decrease the anxiety associated with intercourse. The patient’s partner can help with the techniques, which include gradual development of intimacy and stimulation. Such techniques also can help relieve anxiety when ED from physical causes is being treated. Therapists who specialize in treating patients with issues related to sexuality can be very beneficial for couples dealing with sexual problems.
Hope Through Research
Advances in suppositories, injectable medications, implants, and vacuum devices have expanded the options for men seeking treatment for ED. These advances have also helped increase the number of men seeking treatment. Gene therapy for ED is now being tested in several centers and may offer a long-lasting therapeutic approach for ED.
Points to Remember
- Erectile dysfunction (ED) is the repeated inability to get or keep an erection firm enough for sexual intercourse.
- ED affects 15 to 30 million American men.
- ED usually has a physical cause.
- ED is treatable at all ages.
- Treatments include psychotherapy, drug therapy, vacuum devices, and surgery.
- Almost all men can be helped to have a satsifying sexual relationship with one of the treatments listed above.
- Penile prosthesis surgery, which allows a man to have intercourse whenever he wants without medications, is a successful treatment option for men who do not get adequate improvement from oral medications.
For More Information
Sexual Function Health Council
American Foundation for Urologic Disease
1000 Corporate Boulevard
Suite 410
Linthicum, MD 21090
Phone: (410) 689-3990
Email: impotence@afud.org
Internet: www.impotence.org
American Urological Association
1000 Corporate Boulevard
Linthicum, MD 21090
Phone: 1-866-RING-AUA (746-4282) or (410) 689-3700
Email: aua@auanet.org
Internet: www.auanet.org
American Diabetes Association (ADA)
National Office
1701 North Beauregard Street
Alexandria, VA 22311
Phone: 1-800-DIABETES (342-2383)
Internet: www.diabetes.org
ADA can help you find a doctor who specializes in diabetes care in your area.
American Association of Sex Educators, Counselors, and Therapists (AASECT)
P.O. Box 5488
Richmond, VA 23220-0488
Internet: www.aasect.org
Check the AASECT website to find a certified sexuality educator, counselor, or therapist in your area.