The other 5 percent of prostheses are either pump devices in which the saline is permanently in the prosthesis, not in a separate reservoir (urologists may recommend this for men who have had multiple surgeries); or a pair of semi-rigid, malleable rods implanted in the penis, which render it hard at all times. The patient manually shifts the penis into an erect position for sex.
The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina; it is now mostly replaced by more precise terms, such as erectile dysfunction (ED). The study of ED within medicine is covered by andrology, a sub-field within urology. Research indicates that ED is common, and it is suggested that approximately 40% of males experience symptoms compatible with ED, at least occasionally.[38] The condition is also on occasion called phallic impotence.[39] Its antonym, or opposite condition, is priapism.[40][41]
Inside the cell, NOS catalyzes the oxidation of L-arginine to NO and L-citrulline. Endogenous blockers of this pathway have been identified. The gaseous NO that is produced acts as a neurotransmitter or paracrine messenger. Its biologic half-life is only 5 seconds. NO may act within the cell or diffuse and interact with nearby target cells. In the corpora cavernosa, NO activates guanylate cyclase, which in turn increases cyclic guanosine monophosphate (cGMP). Relaxation of vascular smooth muscles by cGMP leads to vasodilation and increased blood flow.
Stress is your body responding to your environment. And it’s a good thing—in limited doses. When you get stressed out your body makes chemicals like adrenaline that make you stronger, faster, fitter, and even able to think more clearly. Most people call this reaction the “fight-or-flight” response, and it’s a life-saver in dangerous situations. In a very real sense, adrenaline makes you a part-time superhero. The problems happen when your body deals with constant stress.
Since the advent of PDE5i, many other selective and non-selective peripheral acting compounds have been developed or are in development. Avanafil has shown promising results in treating ED in post-prostatectomy patients with suspected cavernous nerve injury (111). Other PDE5i marked in Asia such as udenafil, and mirodenafil also effective at treating ED may minimize side effects due to shorter half-lives (112-114). Soluable guanylate-cyclase inhibitors and potassium channel activators are compounds that have induced erections in animal models but remain experimental requiring further investigation (115-117).

Erythrocytosis has been noted in men on TRT, and should be monitored every 6–12 months depending upon the patients’ response to changes in haematocrit levels. For mild elevations, the dosage of testosterone can be decreased or the interval of using the medication can be increased. With the haematocrit greater than 50%, decisions to temporarily discontinue the medication or periodic phlebotomy may be indicated.38
In most healthy men, some of the drug will remain in the body for more than two days after a single dose of tadalafil. Metabolism (clearing of the drug from the body) of tadalafil can be slowed by liver disease, kidney disease, and concurrent use of certain medications (such as erythromycin, ketoconazole, and protease inhibitors). Slowed breakdown allows tadalafil to stay in the body longer and potentially increase the risk for side effects. Therefore, doctors have to lower the dose and frequency of tadalafil in the following examples:
PDE5i use in PD has not been well studied; however its benefits have been shown. Raffaele performed an open label, prospective study evaluating the efficacy of sildenafil 50 mg on demand and depressive symptoms experienced by the PD patient (73). Erections were improved in approximately 85% of men and 75% noted improvements in their depressive symptoms as well. Sildenafil was well tolerated without significant side effects. Zesiewicz et al., performed a shorter study showing improvements in erectile function but no change in depression and parkinsonisms after ED treatment (74).
PDE5i medications are absolutely not to be taken by men with heart conditions who are taking nitrates such as nitroglycerine or isosorbide (Isordil, Ismo, Imdur). Those with serious heart disease, exertional angina (chest pain), and those taking multiple drugs for high blood pressure are advised to seek the advice of a heart specialist before beginning therapy with sildenafil.
Testosterone replacement: Men with low sex drive (libido) and ED may be found to have low testosterone levels. Hormone replacement may be of benefit by itself or as a complementary therapy used with other treatments. Libido and an overall sense of well-being are likely to improve when serum testosterone levels are restored. The constitution of symptoms of low libido, fatigue, decreased muscle mass and force, and increased body fat may be related to andropause. As mentioned previously, in the patient workup section, serum total testosterone and bioavailable testosterone blood tests can be performed to evaluate for low serum levels. If determined to be below normal, replacement of testosterone may be suggested as a treatment option. The primary objective of testosterone replacement is to improve libido, energy levels, and symptoms of andropause. Only secondarily would correction of low testosterone levels potentially have impact on erectile function. Some studies suggest that in men with low or low normal testosterone levels and ED who fail PDE5 inhibitors that the use of hormone therapy may improve the success of PDE5 inhibitors.
The mechanisms by which testosterone plays a role in erectile function are not completely understood. A study evaluating the effect of testosterone on erections in surgically castrated rabbits and control animals, in which the rabbits’ intracavernosal pressures were compared after cavernosal nerve stimulation, determined that castrated rabbits had much lower pressures after stimulation than control rabbits did. [21] Notably, the pressures increased when castrated rabbits received exogenous testosterone replacement.
Erectile dysfunction can occur as a side effect of medication taken for another health condition. Common culprits are high blood pressure meds, antidepressants, some diuretics, beta-blockers, heart medication, cholesterol meds, antipsychotic drugs, hormone drugs, corticosteroids, chemotherapy, and medication for male pattern baldness, among others.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
Q. I started to suffer from erectile dysfunction? Why is this happening and what can I do to treat it? I am a healthy 52 year old. I have hypertension but i take pills to treat it and my levels are around 130/80. except that I am at great shape. In the last few months I feel that a problem in my sex life. I want to have sex but i can't due to erectile dysfunction. What can be the reason for this? and more important what can I do?

The role of the endothelium in erectile function became clearer with the observation that the phosphodiesterase type 5 (PDE5) inhibitor, sildenafil, enhanced erectile function. Erection occurs with the release of nitric oxide (NO) from the vascular endothelial cells.17 The reduction in endothelial cell production of NO results in the negative impact on the smooth muscles in the corporal bodies and results in less relaxation of the smooth muscle cells with decrease in blood supply and resulting ED. A similar phenomenon is well known to impact the coronary arterial system resulting in CVD.
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older. [15] Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). [16]
Individuals at higher risk for priapism (painful erection lasting longer than six hours), including men with sickle cell anemia, thrombocytopenia (low platelet count), polycythemia (increased red blood cell count), multiple myeloma (a cancer of the white blood cells), and history of blood clots (for example, deep venous thrombosis [DVT]) or hyperviscosity (thick blood) syndrome are at increased risk for priapism with MUSE.

Research is mixed on the effectiveness of acupuncture as an erectile dysfunction cure, but one study published in November 2013 in the Journal of Alternative and Complementary Medicine found that acupuncture can be beneficial for men experiencing erectile dysfunction as a side effect of antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs).


When stimulated by the nerves, the spongy tissue arranges itself in such a way that more blood can be stored in the penis. The veins running through the outer sheath of the penis then compress which stops the blood from leaving the penis. As the blood is stopped from flowing out, the penis fills with blood and stretches within the outer casing, giving an erection.

Certain types of blood pressure medications, antiulcer drugs, antihistamines, tranquilizers (especially before intercourse), antifungals (hetoconazole), antipsychotics, antianxiety drugs, and antidepressants, known as selective serotonin reuptake inhibitors (SSRIs, including Prozac and Paxil), can interfere with erectile function. Smoking, excessive alcohol consumption, and illicit drug use may also contribute. In rare cases, low levels of the male hormone testosterone may contribute to erectile failure. Finally, psychological factors, such as stress, guilt, or anxiety, may also play a role, even when the impotence is primarily due to organic causes.


Following a detailed discussion about the history of erectile dysfunction and its risk factors, your doctor will examine the testicles and penis to help determine the cause of erectile dysfunction. Your doctor will check reflexes and pulses in the area to see if problems with blood vessels or nerves are contributing to the erectile dysfunction. If necessary, your doctor will order tests to help diagnose erectile dysfunction.

"For men who are unwilling or unable to self-inject alprostadil, the FDA has approved this dissolvable pellet that can be inserted directly into the urethra, the opening of the penis," says Dr. Feloney. MUSE, with an inspiring name that actually stands for medicated urethral system for erection, will trigger an erection in about 10 minutes that may last as long as an hour. Using MUSE to treat ED can result in somewhat unpleasant side effects, however — including an aching sensation, burning, redness, and minor bleeding.


Penile prosthesis is the primary form of surgical therapy and is reserved for those men who fail, are intolerant of, or have contraindications to other forms of therapy. Currently, there are several different types of penile prostheses. The simplest is the malleable penile prosthesis, and the most complex is the three-piece inflatable penile prosthesis.
The availability of phosphodiesterase-5 (PDE5) inhibitors—sildenafil, vardenafil, tadalafil, and avanafil—has fundamentally altered the medical management of ED. In addition, direct-to-consumer marketing of these agents over the last 15 years has increased the general public’s awareness of ED as a medical condition with underlying causes and effective treatments.

A variety of lifestyle choices can affect the ability to achieve and maintain an erection, so preventing ED is possible in some cases. Men are encouraged to manage chronic health problems with their doctors and to exercise regularly. They also should avoid smoking and excess alcohol and get help for anxiety or depression, according to the Mayo Clinic.


It starts with your online doctor visit. Your doctor needs to know about your health (e.g., your medications, lifestyle issues, prior surgeries) and how ED affects you. They also need a recent blood pressure (one done in the last 6 months), and personal ID so they know who they will be helping in the coming year. They review everything, determine if you’re a candidate for telemedicine and, if so (most people are), they will craft a personalized treatment plan.

Ultrasound with Doppler imaging (ultrasound plus evaluation of blood flow in the arteries and veins) can provide additional information about blood flow of the penis and may help in the evaluation of patients prior to surgical intervention. This study is typically performed after the injection of a chemical that causes the arteries to open up, a vasodilator (prostaglandin E1), into the corpora cavernosa in order to cause dilation of blood vessels and promote blood flow into the penis. The rate of blood flow into the penis can be measured along with an evaluation of problems with compression of the veins.
While erectile dysfunction can occur at any age, the risk of developing erectile dysfunction increases with age. According to the Massachusetts Male Aging Study, the prevalence of erectile dysfunction was 52% in men 40-70 years of age. The prevalence of complete erectile dysfunction increases from 5% at 40 years of age to 15% among men 70 years of age and older.
Erectile dysfunction is only one cause of sexual dysfunction. Other causes of sexual dysfunction include troubles with ejaculation, decreased libido, and troubles achieving an orgasm (climax). Some men may have premature ejaculation, which is a condition in which the entire process of arousal, erection, ejaculation, and climax occur very rapidly, often in just a few minutes or even seconds, leaving the partner unsatisfied. Premature ejaculation may accompany an erection problem such as ED but is generally treated differently. Troubles with erectile function may lead to decreased libido or interest in sex, however, many men with decreased libido have normal erectile dysfunction. Libido may be affected by psychologic factors, such as stress, anxiety, or depression but often is the result of a low testosterone (the male hormone) level.

The sympathetic pathway originates from the 11th thoracic to the 2nd lumbar spinal segments and goes via the white rami to enter the sympathetic chain ganglia. Subsequently nerves travel through the lumbar splanchnic to inferior mesenteric and superior hypogastric nerves to the pelvic plexus. The T10 through T12 segments are most often the origin of sympathetic fibers, and the sympathetic chain ganglia that innervate the penis are located in the sacral and caudal ganglia (3).
The various PDE5 inhibitors for the treatment of ED share several common side effects, including headache, flushing, nasal congestion, nausea, dyspepsia (stomach discomfort), and diarrhea. Differences exist in side effects of the different PDE5 inhibitors, and thus it is important to be familiar with the prescribing information of the PDE5 inhibitor you are prescribed.

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Penis pumps produce erections by drawing blood, via air suction, into the penis. The devices consist of a cylindrical tube, 12 to 18 inches long, connected by a small air hose to a hand pump (on many models this resembles the squeeze mechanism on a blood pressure monitor). Users place the tube over the penis then pump to produce an erection. They must then place an elastic band around the base of the penis to keep the blood there and maintain the erection.  
It appears that testosterone has NOS-independent pathways as well. In one study, castrated rats were implanted with testosterone pellets and then divided into a group that received an NOS inhibitor (L-nitro-L-arginine methyl ester [L-NAME]) and a control group that received no enzyme. [24] The castrated rats that were given testosterone pellets and L-NAME still had partial erections, a result suggesting the presence of a pathway independent of NOS activity.
PD is a chronic neurodegenerative disease characterized by “motor” and “non-motor” symptoms that lead to progressive disability. Erectile and SD are “non-motor” symptoms and can occur in 50–69% of males with PD (39-42). Ejaculatory and orgasmic function are also impaired. PD affects the dopaminergic pathways leading to erection and arousal. Dopaminergic therapy for PD can improve ED, and sometimes therapy may lead to hypersexuality (43,44). A comparison of married men with PD to age matched controls with non-neurologic chronic disease such as arthritis did not show any discrepancy in ED rates (45). This suggests that ED in certain groups with PD may occur from disease related factors common in chronic illness, in general.
If you can't take one of these oral medications, your physician may have you try Caverject (alprostadil for injection), a hormone that you inject into your penis using a fine needle, or Muse (alprostadil urogenital), a tiny suppository that you insert into the tip of the penis. Both of these will bring on an erection within five to 15 minutes without sexual stimulation.
If you have symptoms of ED, it’s important to check with your doctor before trying any treatments on your own. This is because ED can be a sign of other health problems. For instance, heart disease or high cholesterol could cause ED symptoms. With a diagnosis, your doctor could recommend a number of steps that would likely improve both your heart health and your ED. These steps include lowering your cholesterol, reducing your weight, or taking medications to unclog your blood vessels.
On the horizon is gene therapy that would deliver genes that produce products or proteins that may not be functioning properly in the penile tissue of men with ED. Replacement of these proteins may result in improvement in erectile function. Experimental animal models have demonstrated improvement in erectile function with gene therapy. Human studies may also demonstrate success with this therapy. Gene therapy may take a long time for regulatory approval and public acceptance.
You may find that using a vacuum device requires some practice or adjustment. Using the device may make your penis feel cold or numb and have a purple color. You also may have bruising on your penis. However, the bruises are most often painless and disappear in a few days. Vacuum devices may weaken ejaculation but, in most cases, the devices do not affect the pleasure of climax, or orgasm.
A number of treatments are available to treat erectile dysfunction. The typical treatment strategy starts with simple to use, noninvasive therapies and progresses to more invasive surgical therapies as needed. In all men, the first step is determining if there are any modifiable risks factors that can either improve or prevent progression of erectile dysfunction. Since the risk of developing ED is increased in the presence of diabetes, heart disease, and hypertension, it is thought that better control/prevention of these conditions may have a benefit in ED. Similarly, it is thought that lifestyle modifications to improve vascular function such as avoiding smoking, maintaining ideal body weight, and engaging in regular exercise might either prevent or reverse ED. Sexual counseling may also be useful in addressing relationship stressors as you work on improving your erectile function.
Because impotence can be due to health problems that can affect the whole body, and because it can interfere with one’s quality of life, it is important to talk with your doctor if you have trouble attaining or maintaining an erection. With increasing discussion of impotence in the media, coupled with advances in treatment, men are now much more comfortable talking with their doctors about impotence. It is currently estimated that between 15 and 30 million men in the United States are affected by impotence (Source: NIDDK).

You should talk to your doctor about possible treatments. You may want to talk to other patients who have had the treatment planned for you. You also may want to seek a second doctor's opinion about surgery before making your decision. You may find it difficult to talk to your doctor about impotence. You will want to find a doctor who treats this condition and will help you feel comfortable talking about the problem and choosing the best treatment. You can also get more information by contacting your local National Kidney Foundation affiliate.
Diabetes is a well-recognized risk factor for ED. A systematic review and meta-analysis found that the prevalence of ED was 37.5% in type 1 diabetes, 66.3% in type 2 diabetes, and 52.5% in diabetes overall—a rate approximately 3.5 times higher than that in controls. [39]  The etiology of ED in diabetic men probably involves both vascular and neurogenic mechanisms. Evidence indicates that establishing good glycemic control can minimize this risk.
The other 5 percent of prostheses are either pump devices in which the saline is permanently in the prosthesis, not in a separate reservoir (urologists may recommend this for men who have had multiple surgeries); or a pair of semi-rigid, malleable rods implanted in the penis, which render it hard at all times. The patient manually shifts the penis into an erect position for sex.
Low-intensity extracorporeal shock wave therapy has been proposed as a new non-invasive treatment for erectile dysfunction caused by problems with blood vessels. Shock wave therapy machines are now available in some medical practices in Australia. Although there is some evidence that it may help a proportion of men with erectile dysfunction, more research is needed before clear recommendations on its use can be made.
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