Sexual Dysfunction in Men (Introduction·Decreased Libido· Erectile Dysfunction (ED)· Inability to Ejaculate· Premature Ejaculation· Retrograde Ejaculation)

INTRODUCTION

In men, sexual dysfunction refers to difficulties engaging in sexual intercourse. Sexual dysfunction encompasses a variety of disorders that affect sex drive (libido), the ability to achieve or maintain an erection (erectile dysfunction, or impotence), ejaculation, and the ability to achieve orgasm.

Sexual dysfunction may result from either physical or psychologic factors. Many sexual problems result from a combination of physical and psychologic factors. A physical problem may lead to psychologic problems (such as anxiety, fear, or stress), which can in turn aggravate the physical problem. Men sometimes pressure themselves or feel pressured by a partner to perform well sexually and become distressed when they cannot (performance anxiety). Performance anxiety can be troublesome and further worsen a man's ability to enjoy sexual relations.

Did You Know... Sexual dysfunction may affect the sex drive or the ability to have an erection, to ejaculate, or to have an orgasm. How much of sexual dysfunction is due to physical factors and how much is due to psychologic factors can be difficult or impossible to discern.

Erectile dysfunction is the most common sexual dysfunction in men. Decreased libido also affects some men. Problems with ejaculation include uncontrolled ejaculation before or shortly after penetrating the vagina (premature ejaculation), ejaculation into the bladder (retrograde ejaculation), and inability to ejaculate (anejaculation).

Psychologic Causes of Sexual Dysfunction Anger toward a partner Anxiety Depression Discord or boredom with a partner Fear of pregnancy, dependence on another person, or losing control Feelings of detachment from sexual activities or one's partner Guilt Inhibitions or ignorance about sexual behavior Performance anxiety (worrying about performance during intercourse) Previous traumatic sexual experiences (for example, rape, incest, sexual abuse, or previous sexual dysfunction)

Normal Sexual Function

Normal sexual function is a complex interaction involving both the mind (thoughts, memories, and emotions) and the body. The nervous, circulatory, and endocrine (hormonal) systems all interact with the mind to produce a sexual response. A delicate and balanced interplay among all parts of the nervous system controls the sexual response in men.

Desire (also called sex drive or libido) is the wish to engage in sexual activity. It may be triggered by thoughts, words, sights, smell, or touch. Desire leads to the first stage of the sexual response cycle, excitement. Excitement is sexual arousal. During excitement, the brain sends nerve signals through the spinal cord to the penis. The arteries supplying blood to the erectile tissues (corpora cavernosa and corpus spongiosum) respond by widening (dilating). The widened arteries dramatically increase blood flow to these areas, which become engorged with blood and expand. Muscles tighten around the veins that normally drain blood from the penis, slowing the outflow of blood and elevating blood pressure in the penis. This elevated blood pressure causes the penis to increase in length and diameter, producing an erection. Also, muscle tension increases throughout the body.

In the plateau stage, excitement and muscle tension are maintained or intensified. Orgasm is the peak or climax of sexual excitement. At orgasm, muscle tension throughout the body further increases. The man experiences contractions of the pelvic muscles followed by a release of muscle tension. Semen is usually, but not always, ejaculated from the penis. Ejaculation results when nerves stimulate muscle contractions in the male reproductive organs such as the seminal vesicles, prostate, and the ducts of the epididymis and vas deferens. These contractions force semen into the urethra. Contraction of the muscles around the urethra further propels the semen through and out of the penis. The neck of the bladder also constricts to keep semen from flowing backward into the bladder.

Although ejaculation and orgasm often occur nearly simultaneously, they are separate events. Ejaculation can occur without orgasm. Also, orgasm can occur in the absence of ejaculation, especially before puberty, or with the use of certain drugs (such as some antidepressants) or after surgery (such as removal of the prostate gland). Most men find orgasm highly pleasurable.

In resolution, a man returns to an unaroused state. Once ejaculation takes place or orgasm occurs, penile arteries constrict and the veins relax, reducing blood inflow, increasing blood outflow and causing the penis to become limp (detumescence). After orgasm, erection cannot be obtained for a period of time (refractory period), often as short as 20 minutes or less in young men but longer in older men. The time between erections generally increases as men age.

Decreased Libido Decreased libido is a reduction in sex drive. Possible causes include psychologic factors (such as depression, anxiety, or relationship problems), drugs, and low levels of testosterone. Depending on the cause, doctors may suggest psychologic therapy, prescribe a different drug, or prescribe supplemental testosterone. Sex drive (libido) varies greatly among men. And different men find different degrees of libido satisfactory. Libido may be decreased temporarily by conditions such as fatigue or anxiety. Libido also tends to gradually decrease as a man ages. Persistent low libido may cause a man and his sex partner distress. Occasionally, libido can be low throughout a man's life. Lifelong low libido can result from traumatic childhood sexual experiences or from learned suppression of sexual thoughts. Most often, however, low libido develops after years of normal sexual desire. Psychologic factors, such as depression, anxiety, and relationship problems, are often the cause. Some drugs (such as those used to treat high blood pressure, depression, anxiety, or widespread prostate cancer) and decreased levels of testosterone can also lower libido. A man with decreased libido thinks less about sex. He loses interest in sexual fantasy and masturbation and also in sexual activity. Even sexual stimulation, by sights, words, or touch, may fail to provoke interest. The man often retains the capacity for sexual function. Some men continue to engage in sexual activity to satisfy their partner. A blood test can measure the level of testosterone in the blood. However, the diagnosis is usually based on the man's description of his symptoms. If the cause is psychologic, various psychologic therapies, including behavioral therapies, such as the sensate focus technique (see Sexual Dysfunction in Women: Treatment), can help. Counseling can help address relationship issues. Men should also understand the role of stress and its impact on physical function. If the testosterone level is low,testosterone  can be given, usually as a patch or gel applied to the skin or as an injection (see Biology of the Male Reproductive System: Testosterone Replacement Therapy). If a drug appears to be the cause, a doctor can often try treating the man with a different drug.

Erectile Dysfunction (ED) Erectile dysfunction (impotence) is the inability to achieve or maintain an erection adequate for penetration. The cause may be a disorder that reduces blood flow or damages nerves to the penis, a hormonal disorder, use of certain drugs, or psychologic issues. In many men, sex drive (libido) also decreases. A physical examination (including blood pressure measurement), blood tests, erection testing during sleep, and sometimes ultrasonography may detect a disorder contributing to erectile dysfunction. Drugs, taken by mouth or inserted or injected into the penis, may help, as may constriction and vacuum devices and psychologic therapy. Every man is occasionally unable to achieve an erection, which is normal. Erectile dysfunction occurs when the problem is frequent or continual. Erectile dysfunction can range from mild to severe. A man with mild erectile dysfunction may occasionally achieve a full erection, but more often he achieves an erection that is inadequate for penetration or no erection at all. A man with severe erectile dysfunction is rarely able to achieve an erection. Erectile dysfunction becomes more common with age but is not part of the normal aging process. About half of men 65 years of age and three fourths of men 80 years of age have erectile dysfunction. Causes To achieve an erection, the penis needs an adequate inflow of blood, a slowing of blood outflow, and proper function of nerves leading to and from the penis. Disorders that narrow arteries and decrease blood inflow (such as atherosclerosis, diabetes, high blood pressure, and high blood cholesterol levels) or surgery affecting the blood vessels can cause erectile dysfunction. Also, abnormalities in the veins of the penis can sometimes drain blood back to the body so rapidly that erections cannot be sustained despite adequate blood inflow. Damage to the nerves that lead to or from the penis can produce erectile dysfunction. Such damage could result from pelvic or abdominal surgery (particularly prostate surgery), radiation therapy, spinal disease, diabetes, multiple sclerosis, or peripheral nerve disorders. Other risk factors include stroke, smoking, alcohol, and drugs. Drugs that commonly cause erectile dysfunction (particularly in older men) include antihypertensives, antidepressants, some sedatives, cimetidine  , digoxin  , some diuretics, antipsychotics, and illicit drugs. Occasionally, hormonal disturbances (such as abnormally low levels of testosterone) cause erectile dysfunction. Also, factors that decrease a man's energy level (such as illness, fatigue, and stress) can make it difficult to achieve an erection. Psychologic issues that can cause sexual dysfunction (see Sexual Dysfunction in Men: Psychologic Causes of Sexual Dysfunction) can impair the ability to achieve erections. Psychologic causes are more common in younger men. Any new stressful situation, such as a change of sex partners or problems with relationships or at work, can also contribute. Did You Know... Occasional inability to achieve an erection is normal and does not mean that a man has erectile dysfunction. About half of men older than 65 and one fourth of men older than 80 can usually have erections adequate for penetration. Low levels of testosterone tend to decrease sex drive rather than cause erectile dysfunction. Combinations of drugs injected into the penis and devices that constrict or apply suction to the penis are highly effective and lack many of the side effects of oral drugs. Psychologic therapies can help even when erectile dysfunction has a physical cause. Symptoms Sex drive (libido) often decreases in men with erectile dysfunction, although some men do maintain a normal libido. Regardless of whether libido changes, men with erectile dysfunction have difficulty engaging in intercourse either because the erect penis is not sufficiently hard, long, or elevated for penetration or because the erection cannot be sustained. Some men stop having erections during sleep or upon awakening. Others may attain strong erections sometimes but be unable to attain or maintain erections other times. When testosterone levels are low, the result is more likely to be a drop in libido than erectile dysfunction. In addition, low testosterone levels may lead to thinning of the bones, loss of energy, and loss of muscle mass. Diagnosis To diagnose the cause of erectile dysfunction, a doctor asks about diseases and conditions that may contribute to erectile dysfunction and drugs the man is taking. A general physical examination, including examination of the genital organs and prostate, is performed. The doctor may assess the function of nerves that supply the genitals. Measuring the blood pressure in the legs and assessing the pulses in the legs and feet may reveal a problem with the arteries that supply blood to the penis. A blood sample can be taken to measure the level of testosterone. Certain blood tests can help identify diseases that may lead to temporary or permanent erectile dysfunction, such as diabetes or infection. If a problem with the arteries or veins is suspected, specialized tests may be done. For example, a device can be used at home to measure erections during sleep (when they normally occur). If erections are present during sleep, the cause may be mostly psychologic, whereas if erections are absent during sleep, the cause may be mostly physical. Ultrasonography also can be used to measure blood flow to the penis. Treatment Measures that help prevent or control conditions that contribute to erectile dysfunction, such as high blood pressure, atherosclerosis, and diabetes, may also help improve erectile dysfunction, although the effect may be small. For example, losing excess weight, exercising, and stopping smoking may help. Some men and their partners may choose not to pursue any treatment for erectile dysfunction. Physical contact without an erection may satisfy their needs for intimacy and fulfillment. Sometimes, stopping use of a particular drug can improve erections. Several folk remedies for erectile dysfunction exist, but none have proven to be effective. For men who choose to pursue treatment, there are many choices. Drug Treatment: Many drugs are used to treat erectile dysfunction. Most drugs that are given to treat erectile dysfunction increase blood flow to the penis. Most of these drugs are given by mouth, but some drugs can be applied locally—by injection or insertion into the penis. Sildenafil  , vardenafil  , and tadalafil  are known as phosphodiesterase inhibitors. These are the drugs most frequently used to treat erectile dysfunction. They are effective in about 60 to 75% of men with erectile dysfunction. These drugs are taken by mouth about 1 hour before sexual activity. Tadalafil  is effective for about a day, longer thansildenafil  and vardenafil  , which are effective for about 4 to 6 hours. The drugs are effective only when the man is sexually aroused. Side effects of phosphodiesterase inhibitors include headache, flushing, stuffy nose, upset stomach, and vision problems. More serious side effects, including dangerously low blood pressure, can occur when phosphodiesterase inhibitors are taken with certain other drugs (such as nitroglycerin  or amyl nitrite). Because of this risk, men should not take phosphodiesterase inhibitors if they take nitroglycerin  . Rarely, men taking these drugs have experienced blindness, although it is possible that blindness had nothing to do with taking the drug. Phosphodiesterase inhibitors can cause painful, prolonged erections, but this occurs very rarely. Other oral drugs that have been used to treat erectile dysfunction are phentolamine  ,yohimbine  , and testosterone. They have only limited effectiveness and can have significant side effects. Drugs injected or inserted into the penis widen the arteries and increase blood flow to the penis. Men who cannot tolerate drugs taken by mouth can often be treated with these drugs. An example is alprostadil  , in the form of a pellet (suppository), which can be inserted into the penis through the urethra. It may cause light-headedness, a burning sensation of the penis, or, occasionally, a prolonged, painful erection (priapism—seePenile and Testicular Disorders: Priapism). Because these serious side effects occasionally occur, a man usually takes his first dose under observation in a doctor's office. A man can also induce an erection by injecting drugs (such as alprostadil  alone or a combination of alprostadil  , papaverine  , and phentolamine  ) into the shaft of his penis. Injection is one of the most effective ways to obtain an erection, producing erections in 80 to 90% of men with erectile dysfunction. However, many men are unwilling to inject their penis. Also, the injection is sometimes painful and occasionally causes priapism, and repeated injections may eventually produce scar tissue. Testosterone  replacement therapy may help men whose erectile dysfunction is caused by abnormally low testosterone levels. Unlike other drugs, which work by increasing blood flow to the penis, testosterone works by correcting a hormonal deficiency. Testosterone can be taken in many forms, including patches, topical creams, and injections. Side effects can include liver dysfunction, increased red blood cell counts, and increased risk of stroke. Testosterone replacement alone is rarely adequate to restore erectile function. Whether testosterone increases risk of prostate cancer is unclear, but men taking testosterone should be closely monitored. Constriction (binding) and Vacuum Devices: Erectile dysfunction can often be managed with the use of a constriction device with or without a vacuum device. These devices enable a man to avoid the side effects that can occur with drug treatment. Constriction devices are among the least expensive treatments for erectile dysfunction. These devices (such as bands and rings made of metal, rubber, or leather) are placed at the base of the penis to slow the outflow of blood. These medically engineered devices can be purchased with a doctor's prescription in a pharmacy, but inexpensive versions (often called cock rings) can be purchased in stores that sell sexual paraphernalia. However, the devices are somewhat cumbersome and can cause penile pain, difficulty ejaculating, and bruising. Constriction devices should not be left on for longer than 30 minutes, or they may cause skin breakdown (ulceration). Vacuum devices (which consist of a hollow chamber attached to a source of suction) fit over the penis, creating a seal. Mechanical suction applied to the chamber draws blood into the penis, producing an erection. Many vacuum devices have a constriction device that attaches to the base of the penis. If not, a constriction device can be applied separately. Surgery: When erectile dysfunction does not respond to other treatments, a device that simulates an erection (prosthesis) can be surgically implanted in the penis. A variety of prostheses are available. One type consists of a pair of firm rods, one inserted into each of the corpora cavernosa to create a permanently hard penis. Another prosthesis type is an inflatable balloon that is inserted into the penis. Before having intercourse, the man inflates the balloon with a small internal pump. Surgical implantation of a penile prosthesis requires at least a brief hospital stay and a 6-week recovery before intercourse is attempted. Psychologic Therapy: Some types of psychologic therapy (which include behavior-modification techniques, such as the sensate focus technique—see Sexual Dysfunction in Women: Treatment) can improve the mental and emotional factors that contribute to erectile dysfunction. Psychologic therapy can even help when the erectile dysfunction has a physical cause, because psychologic factors often compound the problem. Specific therapies are selected based on the particular psychologic cause of the man's erectile dysfunction. For example, if the man is suffering from depression, psychotherapy may help with erectile dysfunction. Antidepressants may help erectile dysfunction by relieving depression, but antidepressants may themselves decrease libido and contribute to erectile dysfunction, so their effect may be difficult to predict. Sometimes psychotherapy can reduce anxiety about sexual performance in men with erectile dysfunction from any cause. Improvement may take a long time, and many sessions are usually required. A man, and often his partner, must be highly motivated for psychotherapy to work. Inability to Ejaculate Inability to ejaculate (anejaculation) is usually caused by inability to reach orgasm. It usually occurs as part of erectile dysfunction. Causes, diagnosis, and treatment are the same as for erectile dysfunction (see Sexual Dysfunction in Men: Erectile Dysfunction (ED)). Retrograde ejaculation can sometimes result in absence of visible semen. Premature Ejaculation Premature ejaculation is ejaculation that occurs too early, usually before, upon, or shortly after penetration. The cause is most likely to be anxiety, other psychologic factors, or very sensitive penile skin. Behavior modification therapy, including strategies to delay ejaculation, helps most men. Many males, especially adolescents, ejaculate sooner than they or their partners would like. Premature ejaculation is not just ejaculation that occurs before a man wants it to but rather ejaculation that occurs very soon—often within a minute or two—after penetration. Many experts believe that premature ejaculation almost always results from anxiety or other psychologic causes. Others think that unusually sensitive penile skin may be a cause. Having intercourse less frequently than desired may worsen the problem by making the man even more sensitive. Premature ejaculation is rarely caused by a disease, although inflammation of the prostate gland or a nervous system disorder can cause the condition. Premature ejaculation can distress a man and his partner. If the man ejaculates too early, the partner may be left unsatisfied sexually and may become resentful. Behavior modification therapy can help most men overcome premature ejaculation. A therapist provides reassurance, explains why premature ejaculation occurs, and teaches the man strategies for delaying ejaculation. Other methods that can help a man delay ejaculation include drug treatment (with a selective serotonin reuptake inhibitor, such as fluoxetine  , paroxetine  , or sertraline ), application of an anesthetic to the penis, and use of condoms, which tend to decrease sensation. Sometimes a combination of drug treatment and behavioral therapy enables a man to delay ejaculation even longer than he might be able to with only one of these treatments. When premature ejaculation is caused by more serious psychologic problems, psychologic therapy may help. Learning to Delay Ejaculation Two techniques are commonly used to treat premature ejaculation. They also help reduce the anxiety that often aggravates the problem. Each technique trains the man to experience high levels of excitement without ejaculating. Both involve self-stimulation of the penis (while masturbating) or stimulation by a partner until the man feels that he will soon ejaculate. When done with a partner, stimulation is at first by hand and later before or during intercourse. In the stop-and-start technique, stimulation is stopped. With the squeeze technique, the man or his partner squeezes for 10 to 20 seconds the part of the penis where the head (glans) meets the shaft, preventing ejaculation and decreasing the strength of the erection. In both techniques, stimulation can resume after about 30 seconds. With practice, more than 95% of men learn to delay ejaculation for 5 to 10 minutes or even longer. Retrograde Ejaculation Retrograde ejaculation is a condition in which semen is ejaculated backward into the bladder rather than out through the penis. In retrograde ejaculation, the part of the bladder that normally closes during ejaculation (the bladder neck) remains open, causing the semen to travel backward into the bladder. Common causes of retrograde ejaculation include diabetes, spinal cord injuries, certain drugs, and some surgical operations (including major abdominal or pelvic surgery—one of the most common causes is prostate surgery). Men with retrograde ejaculation can still have orgasms. However, retrograde ejaculation decreases the amount of semen ejaculated out of the penis. Sometimes, no semen comes out. The condition can cause infertility but is otherwise not harmful. Did You Know... Insemination may be possible if infertility is caused by retrograde ejaculation. A doctor makes the diagnosis of retrograde ejaculation by finding a large amount of sperm in a urine sample taken shortly after ejaculation. Men usually need no treatment unless infertility is an issue. About one third of men with retrograde ejaculation improve after treatment with drugs that close the bladder neck (such as pseudoephedrine  ,phenylephrine  , chlorpheniramine  , brompheniramine, orimipramine  ). However, most of these drugs can increase heart rate and blood pressure, which can be dangerous in men with high blood pressure or heart disease. If infertility requires treatment and drugs do not help, doctors can sometimes collect a man's sperm for insemination (see Infertility: Treatment).

Sexual Activity and Heart Disease Sexual activity is generally less taxing than moderate to heavy physical activity and is therefore usually safe for men with heart disease. Although the risk of a heart attack is higher during sexual activity than it is during rest, the risk is still very low during sexual activity. Still, sexually active men with diseases of the heart and cardiovascular system (which include angina, high blood pressure, heart failure, abnormal rhythms of the heart, and blockage of the aortic valve [aortic stenosis]) need to consult their doctor. Usually, sexual activity is safe if the disease is mild, if it causes few symptoms, and if blood pressure is normal. If the disease is moderate in severity or if the man has other conditions that make a heart attack likely, testing may be necessary to determine how safe sexual activity is. If the disease is severe or if the man has an enlarged heart that blocks the flow of blood leaving the left ventricle (obstructive cardiomyopathy), sexual activity should be deferred until after treatment reduces the severity of the symptoms. Sexual activity should also be deferred until at least 2 to 6 weeks after a heart attack. Use of sildenafil  , vardenafil  , and tadalafil may be dangerous in men taking nitroglycerin  , who should not use these drugs. Most often, testing to determine the safety of sexual activity involves monitoring the heart for signs of poor blood supply while the man is exercising on a treadmill. If the blood supply is adequate during exercise, a heart attack during sexual activity is very unlikely.