Erectile dysfunction

Definition
Erectile dysfuntion, or impotence, is the consistent inability to achieve or maintain an erection sufficient for sexual intercourse.

Anatomy
Men become sexually aroused through sight, touch, sound and smell, as well as mental thoughts. When the brain sends messages of sexual excitement to the nervous system, blood flow to the penis increases. The corpora cavernosa, two structures that run the length of the penis, are filled with a spongy material that absorbs this extra blood and causes the penis to enlarge. The corpora cavernosa are covered by a membrane called the tunica albuginea, which traps the blood inside the penis, allowing the erection to be maintained. The erection ends when muscles in the penis contract, reducing blood flow into the penis and opening blood flow out of the penis.

Causes/associated factors
Erectile dysfunction is a common condition. According to a recent study, at least half of all men between ages 40 and 70 may be affected by some degree of erectile dysfunction. Establishing an erection requires proper functioning of the arousal mechanisms, nervous system and vascular system.
Most cases of sexual dysfunction are caused by a physical problem such as a disease, injury or medication side effect. Diseases commonly associated with erectile dysfunction include kidney disease, atherosclerosis (a cholesterol buildup within the blood vessels), blood vessel disease, neurologic disease, multiple sclerosis and diabetes. In fact, up to half of all men who have diabetes experience erectile dysfunction. Nerve injuries that may occur during surgical procedures in the genital or urinary area (particularly prostate surgeries) or traumatic pelvic injuries can also cause erectile dysfunction. Frequent, prolonged bicycling can decrease the blood supply to the penis and cause a temporary erection problem. Erectile dysfunction can be a side effect of many medications, including certain drugs used to treat high blood pressure, heart disease, depression, anxiety, stomach ulcers, seizures and allergies. Hormonal imbalances, heavy smoking, and alcohol or substance abuse may also lead to erectile dysfunction.

In some cases, psychological factors such as stress, anxiety, depression or fatigue may play a role. Relationship problems between partners may also contribute to the condition. Often, the physical and psychological causes of erectile dysfunction overlap. If the dysfunction is related to a physical problem, anxiety over the ability to perform sexually can make the problem worse.

A gradual loss of erections over time typically indicates a physical cause. If the root of the condition is psychological, the dysfunction often appears suddenly, yet erections may continue to occur during sleep or upon waking in the morning.


Signs/symptoms
Most men experience erectile dysfunction from time to time. You may have a complete inability to achieve an erection, an inability to maintain an erection, or an occasional inability to achieve or maintain an erection. If symptoms persist, it's best to consult your doctor.

Diagnosis
The doctor will ask about your medical and sexual history and do a physical exam. Your sexual partner may also be interviewed. Blood tests can help identify or rule out certain diseases that may cause erectile dysfunction. Depending on the test results, the doctor may recommend additional tests. For example, ultrasound (a procedure in which sound waves are used to create an image of internal body parts) can help the doctor evaluate the circulation in your genital organs, and angiography (an imaging technique that allows the study of blood vessels through injection of contrast dye, a substance used with some imaging techniques to create a different density to help study tissues or organs better) can be used to evaluate the vascular structure of your penis. Neurological testing can help the doctor check for nerve damage.
A test to evaluate whether erections occur during sleep (known as nocturnal penile tumescence testing) may be done to help differentiate between psychological and physical dysfunction. Recently, however, studies have shown the information gained from this testing may not be completely reliable. Consult your doctor for details.


Treatment
Depending on the underlying cause, treatment options may include mechanical vacuum devices, medications, surgery or psychological counseling.
Mechanical vacuum devices are external devices used to help draw blood into the penis to achieve an erection. Typically, the penis is first placed in a plastic cylinder. Then, blood is drawn into the penis using a pump to draw air out of the cylinder, which leads to an erection. Finally, a band is placed around the base of the penis to maintain the erection. These devices may not be recommended for certain people, such as those taking anticoagulents.

The drugs sildenafil citrate (brand name Viagra) and vardenafil (Levitra) have been approved by the U.S. Food and Drug Administration for the treatment of erectile dysfunction. They work by relaxing muscles in the penis, which increases blood flow to the corpora cavernosa. Both drugs are taken by mouth one hour before you have sex.

Other medications used to treat erectile dysfunction include papaverine hydrochloride, phentolamine and alprostadil. These quick-acting medications, which increase blood vessel capacity, are injected directly into the penis before sex. Alprostadil is also available in a pellet form that can be inserted into the tip of the urethra. As another option, nitroglycerin can be rubbed on the outside of the penis to enhance blood flow, and oral testosterone may be recommended for men who have low testosterone levels.

Yohimbine, a prescription medication that's made from the bark of the yohim tree, is thought to improve blood flow and may be helpful for some men. More research is needed, however. Other medications and herbal remedies for erectile dysfunction are also being studied. All medications have possible side effects and drug interactions, and some should not be used if you have certain medical conditions. Be sure to discuss your medication options with your doctor.

Surgical procedures may help increase or sustain blood flow to the penis. Penile implants are another surgical option. Often, they're inflatable or semirigid devices that are implanted into the penis to restore erections. The user typically controls the expansion of the devices. Possible problems may include infection or mechanical breakdown.

Kegel exercises, contracting and relaxing the pelvic muscles used to control urination, may be recommended several times a day for erectile dysfunction that's caused by decreased blood circulation.

Psychological counseling may be helpful if the erectile dysfunction has a psychological cause. Your partner may be encouraged to attend the counseling sessions as well.


Complications
Sexual performance is closely linked with self-identity, so any inability to perform sexually can be emotionally devastating. Some men may be reluctant to discuss the situation or their concerns with their partners. Others may avoid sex altogether, which can lead to a variety of relationship problems. Your partner may feel unwanted or inadequate, or begin to worry about your feelings for her or him. Open communication between partners is crucial for preventing relationship problems.

Senior-specific information
Although not all older men are affected, erectile dysfunction is most common in men over age 65. With age, it's common to require more stimulation to get an erection, as well as more time between erections. You should still be able to achieve an erection and enjoy sex, however.
Older adults are also more likely to develop diabetes, kidney disease, atherosclerosis and other chronic diseases. These conditions give older men a greater risk of developing erectile dysfunction. If you notice a consistent or recurring inability to perform sexually, consult your doctor.


Prevention
A healthy lifestyle may help reduce the risk of developing erectile dysfunction. Get an adequate amount of sleep, exercise regularly, eat healthfully, and limit your alcohol intake. If you smoke, stop. If you're experiencing anxiety, stress or depression, seek professional treatment. Finally, avoid the use of recreational drugs.