Erectile Dysfunction - Treating Common Sexual Problems: Womens Sexual Health

Content provided by the Faculty of the Harvard Medical School

Erectile dysfunction

There's been a revolution in the treatment of erectile dysfunction. As a result, a problem that was once spoken of only in whispers is now a topic for daytime TV. Although it still isn't easy to acknowledge intimate problems, the openness allows men with this condition to see that they are not alone.

Because many men are reluctant to acknowledge erection difficulties, it is difficult to determine just how common the problem is. However, the American Urological Association estimates that erectile dysfunction affects 25 million American men. While it can strike any man who is old enough to have an erection, erectile dysfunction becomes more common with age. One study found that approximately 40% of 40-year-old men, 50% of 50-year-old men, and 67% of 70-year-old men had some degree of erectile dysfunction.

Don't let these numbers fool you into thinking that erectile dysfunction is an inevitable part of aging. It isn't. Although age-related changes such as lower testosterone levels, decreased blood flow to the genitals, slower nerve function, less elastic erectile tissue, and increased stress all play a part, even these factors don't fully explain all the numbers. The problem often results from an illness that becomes more prevalent with age — such as cardiovascular disease or diabetes — or its treatment. Many of these conditions can be prevented with good health habits such as following a healthy diet, exercising regularly, maintaining a normal weight, and not smoking.

How an erection occurs

At its most basic level, an erection is a hydraulic event. Blood fills the penis, causing it to swell and become firm. But getting to that stage requires an extraordinary orchestration of body mechanisms. Most of the time, an erection really starts in the man's brain. A sight, smell, or touch sparks electrical signals of sexual arousal in the brain. These signals travel from the brain to an area in the lower part of the spinal cord. Nerves in this area signal nerves in the pelvis, which instruct arteries to let blood into the penis, thereby causing an erection.

Direct genital stimulation can also produce an erection, but different nerve pathways are involved. In this case, the sensation is carried by the pudendal nerve, which runs from the penis to nerves in the lower spine. Then these nerves send messages that cause the arteries in the penis to admit blood.

How is blood flow increased? Nerve cells use chemical messengers to talk to one another. These messengers boost the production of another set of chemicals, which initiates the erection by relaxing the smooth muscle cells lining the tiny arteries that lead to the corpora cavernosa, the pair of flexible cylinders that run the length of the penis (see Figure 3). As the arteries relax, thousands of tiny caverns inside these cylinders fill with blood. Blood floods the penis through two central arteries, which run through the corpora cavernosa and branch off into smaller arteries. The amount of blood in the penis increases sixfold during an erection. The blood filling the corpora cavernosa compresses the openings to the veins that normally drain blood away from the penis, temporarily closing them off. The blood is, in effect, trapped in the penis for the duration of the erection.

Obviously, an erection isn't permanent. Some signal — usually an orgasm, but possibly a distraction, interruption, or even cold temperature — brings an erection to an end. This occurs when the chemical messengers that started and maintained the erection stop being produced and other chemicals destroy the remaining messengers. Blood seeps out of the caverns of the corpora cavernosa, allowing the veins in the penis to reopen and drain blood from the penis.

Figure 3: What happens during an erection When a man is sexually stimulated, chemical signals from the brain cause the penile arteries to widen, allowing more blood to enter the erectile bodies known as the corpora cavernosa. The tissues swell with blood, causing an erection. At the same time, blood-engorged tissues compress the veins, keeping blood in the penis and maintaining the erection.

Causes of erectile dysfunction

In the past, most cases of erectile dysfunction were considered psychological, the result of such demons as performance anxiety or more general stress. Although these factors do cause some cases of erectile dysfunction, doctors now think that 70% of erectile dysfunction can be traced to age-related changes or a physical condition that hampers blood flow, nerve functioning, or both. Such conditions include diabetes, kidney disease, atherosclerosis, vascular disease, multiple sclerosis, and alcoholism. (See "Sexuality and health problems.") Less frequently, erectile dysfunction is an outgrowth of injury to the nerves and vessels that serve the genitals or a disease that causes scarring of penile tissue.

Unhealthy habits can also raise a man's risk of erectile dysfunction. A 2006 study in the Journal of Urology by Harvard researchers showed that smoking raises the risk of erectile dysfunction by 50%, while being obese increases risk by 90%. Men who were both overweight and sedentary were two and a half times as likely to have erectile dysfunction compared with active men of normal weight.

But thinking of erectile dysfunction as either psychological or physical can be misleading. These forces are usually intertwined. In fact, more than 80% of men with erectile dysfunction caused by an underlying physical illness develop psychological issues that further hamper erections.

Diagnosing the problem

Before going to your doctor, it's important to understand what erectile dysfunction really is. Failure to get an erection after one too many drinks or during a week of intense stress doesn't constitute erectile dysfunction. Also, normal changes in your sexual response as you age — such as having to wait a longer time after orgasm to have another erection or needing more direct stimulation — don't necessarily fall under this heading.

Erectile dysfunction is the inability to attain and maintain an erection sufficient for sexual intercourse at least 25% of the time. The penis doesn't get hard enough, or it gets hard but softens too soon. The problem generally comes on gradually. When such difficulties occur regularly and distress you or your partner, it's time to talk to your doctor.

There are many therapies — such as oral medications, injections, sex therapy, mechanical devices, and surgery. Doctors typically try to diagnose the cause of the problem before recommending a treatment. The doctor will ask about your symptoms and your health history, including any diseases and surgeries you've had and medications you're taking. The doctor will ask about feelings of depression, your stress level, and your relationship with your partner.

During a 10- to 15-minute exam, the doctor will check for conditions that can affect blood flow, such as high blood pressure or a heart murmur. He or she may test your blood to assess your risk for cardiovascular disease. The doctor will also examine your testicles, penis, and chest (small testicles and enlarged breasts are signs of low testosterone). In addition, your doctor will feel your prostate gland and test your reflexes. Now that medication can successfully treat most cases of erectile dysfunction, many once-routine diagnostic tests are rarely used. Still, if your doctor suspects that you have another condition that requires treatment, he or she may order a specialized test (see below).

Once your doctor identifies the cause of your erectile difficulty, you can begin treatment. Several options are available.

Viagra, Levitra, and Cialis

When sildenafil citrate (Viagra) came onto the market in the late 1990s, it revolutionized the treatment of erectile dysfunction. The famous "little blue pill" is safe, easy to use, and effective for a broad range of causes — qualities that made it the first-line treatment for most men with erectile dysfunction. Its success spawned competitors like vardenafil (Levitra) and tadalafil (Cialis), both of which were approved by the FDA in 2003.

All three medications work in much the same way: By relaxing smooth muscle cells, the drugs widen blood vessels primarily in the penis, as well as in other parts of the body. For many men, this clears the way for an erection. These pills aren't aphrodisiacs; you've got to feel desire and be sexually stimulated in order for them to work. But if they are taken 15 minutes to an hour before intercourse, they can help you get and maintain an erection by acting on the normal physiology of the penis.

The three medications have similar success rates. In all, about 70% of men respond well to the drugs, but the rates vary according to what is responsible for the erectile dysfunction. Men with impotence of no identifiable physical cause fare best, while the drugs are less effective for men with diabetes or who have had prostate cancer surgery.

The three rivals also have similar side effects. For all, side effects are uncommon and mild when the drugs are used properly. The most common side effect is headache, which occurs in about 16% of men. Other reactions include flushing, nasal congestion, indigestion, urinary tract infections, and diarrhea. A few men who take Cialis have backaches, while a few Viagra and Levitra users have reported vision problems, typically a temporary blue tinge or haze.

There have been reports that a very small number of people using Viagra, Levitra, or Cialis have experienced vision loss. However, it's not clear that there is a cause-and-effect relationship between these medications and NAION (nonarteritic anterior ischemic optic neuropathy), a condition that can lead to blindness. While the concern isn't great enough to prevent men who need these medications from using them, it serves as a reminder to get regular eye care and remain alert for possible side effects.

While these drugs are safe for men with healthy hearts, men with cardiovascular disease should take special precautions, and some cannot use them at all. If you have had a recent stroke or heart attack, have low or high blood pressure, congestive heart failure, unstable angina, or heart arrhythmia, talk to your doctor about whether these drugs are safe for you. If you are taking medication containing nitrates (such as nitroglycerine for angina), you should avoid Viagra, Levitra, or Cialis. Mixing these medications can cause blood pressure to drop to dangerously low levels. In addition, men taking alpha blockers (medications used to treat high blood pressure and benign prostatic hyperplasia) should not take Levitra or Cialis, but they may be able to use Viagra with caution.

While Viagra, Levitra, and Cialis are quite similar, there are some differences. For example, the starting dosages are different for each. While you should take Viagra on an empty stomach, you can take Cialis or Levitra with or without food.

These medications may take effect in as little as 15–20 minutes or up to an hour. Viagra and Levitra last for about 4–5 hours, but Cialis stays active in the body far longer — for up to 36 hours. (Of course, this doesn't add up to a day-long erection. Cialis simply makes an erection possible during that period if desire and sexual arousal are present.)

Despite their impressive results, these medications have some drawbacks. Since they can take up to an hour to work, you'll need to plan accordingly. Also, they are relatively expensive, costing about $10 to $14 a pill. Some insurance plans do not cover this expense; others allow for only a few pills a month. Even if you don't think you'll use all the pills allotted to you each month, you might consider ordering them anyway so that you'll have extras on hand for vacations or special occasions.

Penile injections

For men who can't or don't want to use Viagra, Levitra, or Cialis, injecting medication directly into the side of the penis with a tiny needle is an effective option (see Figure 4). Injection therapy works better than erectile dysfunction pills for men whose erectile difficulties result from diabetes or prostate cancer surgery. Your doctor or nurse can demonstrate the injection technique, which most men are able to learn quickly. An erection typically occurs 5–20 minutes after an injection and lasts for 30–60 minutes. Only one drug, alprostadil (Caverject and Edex), is approved specifically to treat erectile dysfunction in this manner, although several older drugs used for other purposes are also effective. These include papaverine (Pavabid, Genabid, and others), phenoxybenzamine (Dibenzyline), and phentolamine (Regitine).

Figure 4: Injection therapy If your erectile dysfunction is caused by diabetes or prostate surgery, you may find that injection therapy is more effective than Viagra, Cialis, or Levitra.

The main side effects are mild to moderate pain, bruising, or scarring. Injectable drugs can cause low blood pressure, although this typically happens only if a man takes a large dose or injects himself more than once in 24 hours. Another rare complication is priapism, an erection that lasts too long. If you have an erection that lasts more than three hours after injection, you should go to the emergency room to avoid severe damage. An erection that lasts longer than six hours can cause scarring and complete loss of erectile function.

Drug pellets and MUSE

An alternative to injections is a therapy called MUSE (Medicated Urethral System for Erection). In this procedure, you use a disposable plastic applicator to insert a pellet of the drug alprostadil (the same drug that's used in injections) about an inch up the urethra. From there the drug is quickly absorbed into the erectile tissues, where it dilates the arteries. Some men find it easier to use than injections; however, clinical experience shows it's effective in only about 30% of men.

Mechanical devices

Men who can't or don't want to use medications can opt for mechanical devices that assist in producing an erection, maintaining an erection, or both.

• Penile band. If you can get an erection but lose it because of leakage of blood from veins in the penis, you may find a penile band helpful. This band is fastened around the base of the penis to prevent blood from escaping. Available without a prescription under the brand names Actis and Erexel, the bands are very effective when used properly.

• Vacuum erection device. This consists of an airtight plastic cylinder that's attached to a manual or battery-operated handheld pump. You insert your penis into the cylinder and pump out the air, which increases blood flow to the penis. It takes about five minutes to get an erection. At that point, you fit a rubber ring around the base of the penis to prevent the blood from draining away. The erection lasts until the ring is removed. Although vacuum pumps are about 80% effective and can be used as frequently as a man wishes, they have some drawbacks. Some men find the pump hard to use, the process may be disruptive to lovemaking, and the man's erection does not feel as natural as one produced with medication. Minor side effects such as pain, bruising, and difficulty ejaculating occur in 10% of men who use the pump.

Surgical implants

This option is reserved for cases where no other form of treatment has succeeded. Two kinds of implants are available. The first consists of two pencil-thin silicone rods implanted in the penile shaft above the urethra. The operation is done on an outpatient basis and takes about an hour. Afterward, the penis remains permanently erect, although it can be pointed down along the thigh to conceal it under clothing.

The second type of implant uses inflatable cylinders that are placed into the corpora cavernosa. When the man wants an erection, he simply squeezes a pump located in the scrotum. The pump pushes saline fluid into the cylinders from a reservoir implanted in the scrotum or abdomen. Although this device generates a more natural erection than silicone rods, it's prone to complications, such as infection or malfunction.

Treatment for specific disorders

For men whose erectile dysfunction can be traced to a specific disease, the following treatments are available.

• Vascular surgery. When erectile dysfunction results from leakage of blood from certain veins during an erection or the blockage of specific blood vessels, surgery may correct the problem. To treat leakage, the surgeon ties off the leaking vessels so they retain blood. In the case of a blockage, the surgery entails bypassing the damaged vessels to allow more blood into the penis. These operations are able to restore normal erectile function less than 30% of the time.

• Surgery for Peyronie's disease. In Peyronie's disease, scar tissue makes the penis bend during an erection. Surgery usually involves cutting a notch on the outside curve of the penis, then stitching the ends together. If there is too much scar tissue, the damaged portion is removed and replaced with a graft of skin tissue. However, if the underlying arteries are damaged during the surgery, the procedure could result in erectile dysfunction.

• Hormone therapy. Testosterone supplements are appropriate only if you have abnormally low levels of this hormone. The supplements can help boost your libido and improve your ability to have erections. These supplements are now nearly always given in gel form, which you apply daily to your shoulders. Other forms are less convenient (doctor-administered injections) or cause skin irritation (skin patches). The exact role that low testosterone plays in erectile dysfunction remains unclear. However, at least one study suggests that using testosterone gel along with Viagra may be helpful for men with low or borderline testosterone levels who don't respond to Viagra alone.

How sex therapy can help

Sex therapy is often helpful for erectile dysfunction, even when physical factors are to blame. Sexual difficulties, no matter what the cause, can strain your relationship. Frequently a man with erectile problems experiences performance anxiety, which makes him reluctant to initiate sexual contact. His partner may perceive this as rejection, which could trigger feelings of frustration and resentment. But sex therapy can help a couple overcome these feelings and reestablish intimacy.

In addition to standard sensate focus techniques, the therapist will teach the couple techniques for overcoming worries about losing an erection during sexual activity. For example, in one case, a man and his partner would progress to the stage of stimulation where intercourse would normally begin, then purposely stop so that the penis becomes flaccid again. Then they resume stimulation until the man has an erection again. When they do this exercise repeatedly, the couple learns to relax, knowing that the man will be able to regain his erection if he loses it.

It's common for sex therapy to be used along with medications for erectile dysfunction. Doctors often prescribe drugs to help men overcome performance anxiety in the short term and recommend sex therapy to help the couple work through the emotional component of the problem. Once confidence is restored, some men are able to have erections without taking Viagra or similar medications.

Last updated:	January 23, 2007