Erectile Dysfunction (ED), sometimes called impotence is a repeated inability to achieve or keep an erection firm enough for sexual intercourse. The word impotence may also be used to describe other problems that interfere with sexual intercourse and reproduction, such as a lack of sexual desires and problems with ejaculation and orgasm but the term Erectile Dysfunction is more precise because it refers only to erection problems. Men with erection problems often retain other sexual functions. For example, they may have sexual desire and may still be able to have orgasms and ejaculate semen.
It is estimated that about thirty million men in the United States experience chronic erectile dysfunction. Studies show that about half of the men between the ages of 40 and 70 have ED to some degree. Until recently, there was only a little choice of treatment in cases of diminished erection or impotence. Fortunately, times have changed. Due to the fact that research has been successful over the years, men may now be treated for this problem. Possible therapies include medications, injections, sexual counseling and surgery. Most erection disorders are caused by a combination of physical and psychological problems. Urologists who have traditionally treated erectile dysfunction.
ANATOMY OF THE PENIS
The penis contains two chambers called the corpora cavernosa, which run the length of the organ. A spongy tissue fills the chambers. The corpora cavernosa are surrounded by a membrane called the tunica albuginea. The spongy tissue contains smooth muscles, fibrous tissue, spaces, veins, and arteries. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa.
HOW IS THE PENILE ERECTION ACHIEVED?
The physiological process of an erection begins in the brain and involves the nervous and vascular systems. The brain, for example, is where sensation of sexual arousal is experienced. The brain sends its arousal signal to the penile nerves. Nerves play and important role in achieving erections. Nerves are the pathways from the brain and spinal cord to the penis and are involved in releasing chemicals called neurotransmitters. The nerve impulses go to the two erection chambers, the corpora cavernosa. The corpora cavernosa are two cylinders side by side in the penis. Covering them is a dense, elastic fibrous envelope called the tunica albuginea. There, the nerve impulses cause relaxation of penile tissue and expanding of arterial blood supplies. As the penile tissue relaxes and penile arteries expand, the blood flow into the erection chambers increases. The penis then swells in size. Veins that drain the blood are compressed against the inner wall of the tunica albuginea. The blood is thus trapped, making the penis hard and erect. Continued stimulation keeps the process going and maintains an erection. When stimulation ends or following ejaculation, pressure in the penis decreases, blood is released, and the penis resumes its normal shape.
TYPES OF ERECTILE DYSFUNCTION
There are different levels of erectile dysfunction. One is when the penis does not harden enough or at all. The second type is when the penis does get somewhat erect, but not hard enough to allow intercourse. The third possibility is that the penis does not get erect normally,but then softens again too quickly.
WHAT CAUSES ERECTILE DYSFUNCTION?
Since an erection is caused by a precise sequence of events, erectile dysfunction can occur when any of the events is disrupted. Very often, an erectile problem will have more than one cause. The causes may be psychological or physical, or a combination of both. Distinguishing between psychological and physical causes is helpful because treatment may differ depending on the cause. Today, experts believe that 80-90% of all erectile dysfunction cases may be due to physical conditions with psychological factors accounting for the remaining 10-20%. In many cases, however, there are both psychological and physical reasons for the condition.
CAUSES OF ERECTILE DYSFUNCTION
There are many classification systems for the causes of ED. The easiest is to categorize the causes as physical, psychological, neurological, vascular and other. Reduced blood flow to the penis and nerve damage is the most common causes of erectile dysfunction. Underlying causes include the following: vascular disease, diabetes, drugs, hormone imbalance, neurological causes, pelvic trauma in surgery, Peyronie's disease, and venous leak.
Vascular Disease: Vascular disease is the predominant cause of erection problems. Low blood flow in and around the heart may cause a cardiac infarct, the same problem in the brain may cause a stroke, and in the penis it causes erection problems. Another cause of erection trouble may be the venous leak. If the veins that drain blood from the cavernous bodies in the penis do not sufficiently close during erection, it causes blood and pressure to leak out of the penis, which in turn will make it impossible to build up enough blood pressure in the cavernous bodies for sufficient erection.
Diabetes: Diabetes is a major cause of erection problem. Between 35 and 50% of men with diabetes experience erectile dysfunction and 50% of all diabetic men become impotent after age 50. The disease can damage blood vessels and nerve tissues. Both may have an effect on erection. High levels of blood sugar associated with diabetes often damage small blood vessels and nerves throughout the body, which can impair nerve impulses and blood flow necessary for erection.
Other: Drugs and vices, like drinking alcohol or smoking, may damage the nerves and blood supply needed for normal erection. There are over 200 prescription drugs that may cause or contribute to impotence, including drugs for high blood pressure, heart medication, antidepressants, tranquilizers and sedatives.
Hormonal Imbalance: Testosterone deficiency can result in a loss of libido (sexual desire) and a loss of erection. Low testosterone account for 1% of ED. High production of prolactin and high or low thyroid hormone levels (hyperthyroidism or hypothyroidism, may add to a low testosterone production and thus, cause a lower libido. Hormonal imbalances can also occur as a result of kidney or liver disease.
Neurological Causes: Multiple sclerosis, Parkinson's disease, and spinal cord injuries are among those that may lead to loss of potency. Spinal cord and brain injuries can cause impotence because they interrupt the transfer of nerve impulses from the brain to the penis.
Pelvic Trauma in Surgery: Surgery of the colon, prostate, bladder, or rectum, may damage the nerves and blood vessels involved in erection. Surgeries, especially the radical prostate surgery for cancer, can injure nerves and arteries near the penis, causing erectile dysfunction. Injury to the penis, spinal cord, prostate, bladder, and pelvis, can lead to erectile dysfunction by harming nerves, smooth muscles, arteries, and fibrous tissues of the corpora cavernosa. Removal of the prostate or bladder often results in impotence. There are some new nerve-sparing techniques aimed at lowering the incidence of impotence from 40% to 60% are now being developed and used in these surgeries. Read more about the da Vinci Robotic surgery for prostate cancer removal.
Peyronie's Disease: Peyronie's disease is an inflammatory condition that causes scarring of the erectile tissue. The French surgeon Francois de la Peyronie first described it in 1743. It is estimated that up to 1-4% of all men may have some form of it. The scar tissue, or Peyronie's plaque, forms in the wall of the tissue that surrounds the corpus cavernosum. This is the structure that fills with blood to create a normal erection. When the plaque is large enough it may interfere with the ability of the muscles within the corpora to compress the veins that drain the penis during an erection. Therefore blood leaks from the penis back into the general circulation, making it impossible to maintain an erection. The penis is curved. Most cases occur between 40-70 years of age but it can develop at any time. The cause of Peyronie's disease is unknown, although trauma to the penis has been implicated. This curvature can be so severe that it prevents intercourse.
Psychological Causes: Though the physical reasons for ED are many, once a man has difficulty with erections, psychological factors often become a factor. Men who experience a sudden loss of erectile capability often have a psychological origin to their condition. Just as an erection can result from thinking about sex, negative thoughts can prevent an erection from occurring. In addition, depression and other psychological problems can affect both erections and sexual drive. Typically, patients whose erectile dysfunction is primarily psychological in nature continue to have erections while they sleep or when they get up in the morning. Psychological causes of impotence can include stress or anxiety from home or work, worry about poor sexual performance, marital problems, unresolved sexual orientation and depression. Psychological factors in impotence are often secondary to physical causes, but they magnify their significance.
WHICH DOCTORS TREAT E.D.?
As a group, urologists are the most knowledgeable about erectile dysfunction. Urologists regularly diagnose and treat the condition and who stay up to date on the latest ED research and treatments. Many psychiatrists and psychologists also treat the condition. It is very important that medical professionals discuss the pros and cons of all treatment options with their patients.
FINDING THE CAUSE OF ERECTILE DYSFUNCTION
Medical History: The first visit with start with an extensive medical history, including psychological and sexual aspects of your life. Remember, there are many potential causes for impotency, and most of these are identified in a detailed history. The doctor will also interview the patient for possible risk factors. The doctor will ask questions about stress and fatigue and the relationship between you and your partner. This will probably include questions of a personal nature, but they are necessary to get an overview of your whole sex life. Further information obtained regarding lifestyle issues such as smoking and illicit drug use may affect the man's ability to obtain an erection, and this information is equally as important. The doctor will also make sure to ask questions about any contributing factors to your erection problems, like diabetes, alcohol abuse, medications, etc. Once a medical history is complete, a physical exam will follow.
Physical exam: A physical exam is straightforward and can give clues to systemic problems. For example, if the penis is not sensitive to touching, a problem in the nervous system may be a cause. Abnormal secondary sex characteristics, such as hair patterns, can point to hormonal problems, which can mean that the endocrine system is involved. The examiner might discover a circulatory problem by observing decrease pulses in wrists and ankle. An unusual characteristic of the penis itself could suggest a source of the problem. For example, a penis that bends or curves when erect could be the result of Peyronie's disease. The physician may also do a rectal exam to check the condition of the prostate and also feel the thyroid gland.
Laboratory: Blood tests can indicate conditions that interfere with normal erectile function. These tests measure hormonal levels, such as testosterone, cholesterol, blood sugar (diabetes), liver and kidney function, and thyroid function. As mentioned early, excessive prolactin can lower testosterone levels, which can diminish libido. A urinalysis may be ordered to rule out bladder infections. If necessary, additional special tests may be conducted.
A high frequency sound wave (ultrasound) is used to check the condition of the penile arteries. Ultrasound is used to evaluate blood flow, venous leaks, signs of atherosclerosis, and scarring or calcification of the erectile tissue. Another test is observing the response to drugs that normally stimulate an erection when injected into the penis. Erection is induced by injecting prostaglandin, a hormone-like stimulator produced in the body. Ultrasound is then used to see vascular dilatation and measure the penile pressure, which may also be measured with a special cuff. Measurements are compared to those taken when the penis is flaccid.
The Nocturnal Penile Tumescence (NPT) test, the patient attaches a pair of special guages to his penis before going to sleep. Normally, men of all ages have erections during the dreaming (rapid eye movement) stages of their sleep. The NPT test measures those erections. If no nocturnal erection occurs, or if the erection is impaired, the causes of Erectile dysfunction are likely to be physical. By contrast, a normal NPT in a man with erectile dysfunction suggests a psychological cause. Many of these test were previously done in centers and cost about $1000.00-$4000.00 per night. The patient would be required to stay three to four nights to get the best results. For a more reasonable cost, monitors that check erections of men sleeping at home are now available. One of these is the Rigiscan® a small take home computer.
The ultimate test for the arteries of the penis is arteriography. A radiologist places a small tube in the femoral artery in the upper thigh, then finds the artery that goes to the penis (pudendal artery) and injects contrast dye to show blockages in the penile arteries. A physician performs this test only when considering surgery to unblock the artery or bypass a blockage, usually on young men with a previous history of trauma to the penis.
Cavernosometry/Cavernosography: This is the definitive test for venous leak. In normal erection, the swelling of the penile tissue pinches off the veins to prevent blood from leaving the penis. With the condition called venous leak, the blood goes into the penis, then immediately leaks out of the veins. Cavernosometry evaluates if venous leakage occurs. Cavernosography is then performed to identify where the leak is. Physicians usually do this rare test only when they want to find the exact cause of impotency or fix the leak.