Erectile dysfunction is defined as the persistent inability to achieve or maintain penile erection sufficient for satisfactory sexual performance. The Massachusetts Male Aging Study surveyed 1,709 men aged 40–70 years between 1987 and 1989 and found there was a total prevalence of erectile dysfunction of 52 percent. It was estimated that, in 1995, over 152 million men worldwide experienced ED. For 2025, the prevalence of ED is predicted to be approximately 322 million worldwide.
Because the burning side effect is triggered by alprostadil, the formulations with the least alprostadil — tri-mix and certain versions of bi-mix — could work for men who experience burning with the single-drug formula. But some men might choose alprostadil alone because the multi-drug cocktails can cost more and must be dispensed by a compounding pharmacy — one that is authorized to mix medications on site — which could mean the added hassle of a long drive to pick up the drug.
Erectile dysfunction is known to be associated with general health status, thus, lifestyle modification improves erectile function and decreases the rate of decline of function with aging. One year after discontinuation of smoking, patients were found to have a 25% improvement in erectile quality.16 In addition, multivariate analysis found obesity is associated with erectile dysfunction with an approximately 50% increase in ED in obese men as compared with normal weight men.17
The most common treatment for erectile dysfunction is drugs known as phosphodiesterase-5 (PDE-5) inhibitors. These include tadalafil (Cialis), vardenafil (Levitra), and sildenafil citrate (Viagra). These are effective for about 75% of men with erectile dysfunction. They are tablets that are taken around an hour before sex, and last between 4 and 36 hours. Sexual stimulation is required before an erection will occur. The PDE-5 inhibitors cause dilation of blood vessels in the penis to allow erection to occur, and help it to stay rigid. Men using nitrate medication (e.g. GTN spray or sublingual tablets for angina) should not use PDE-5 inhibitors.
According to whom? What's the source of your statistic? Because it sounds astonishingly high, for me to get erections and then lose them. If what you are talking about is men not being able to get erections, why don't you be honest and say that normally this is completely associated with age (say, over-60, and especially over 75), and that the Viagra-class of medications is the simplest and easiest response.
Occasional successful sexual function and early morning erections do not preclude the possibility of endocrine dysfunction. Since abnormally low levels of testosterone frequently are the primary cause of impotence, it is recommended that determination of the blood level of testosterone be an integral part of the total evaluation of the impotent patient.

Size matters, so get slim and stay slim. A trim waistline is one good defense — a man with a 42-inch waist is 50% more likely to have ED than one with a 32-inch waist. Losing weight can help fight erectile dysfunction, so getting to a healthy weight and staying there is another good strategy for avoiding or fixing ED. Obesity raises risks for vascular disease and diabetes, two major causes of ED. And excess fat interferes with several hormones that may be part of the problem as well.
Over a 2-year period, a third of the men randomized to a weight loss program demonstrated resolution of erectile dysfunction.10 A Mediterranean diet and nutritional counseling reported increased erectile quality.18 Little evidence supports that increased physical activity alone improves erectile quality; however, the strong association between physical activity and lower BMI is well described, and therefore recommended for men with erectile dysfunction and without a contraindication to physical activity.
Psychosocial problems are important and may cause erectile dysfunction by themselves or together with other causes of erectile dysfunction, such as diabetes and heart disease. Relationships are complicated and many factors cause tensions, which can affect sexual relations. For some men, these problems can become ongoing and it can help to talk through the issue with a skilled counsellor. It is important to know that the longer erectile dysfunction is left untreated, the greater the effect on relationships. This is another reason why early treatment of erectile dysfunction is important.
There are many different treatment options for erectile dysfunction but your individual diagnosis will determine which treatment option is right for you. It is important to realize that not all treatment options will work for everyone. A doctor who has specialized in men’s sexual health (typically a urologist) will be the most qualified to discuss all of your treatment options with you. Many specialists will often encourage you to schedule additional follow up appointments to review how your treatment is working for you or if a different option may be more beneficial.

Inflatable prostheses are complex mechanical devices that imitate the natural process of erection. Parts are inserted surgically into the penis and scrotum, and activated by squeezing. When erection is no longer desired, a valve on the pump is pressed, and the penis becomes flaccid. Self-contained single-unit prostheses are similar to the inflatable types, but more compact. The entire device is implanted into the penis. When erection is desired, the unit is activated by either squeezing or bending, depending on which of the two types of self-contained prostheses is used.
Erections are initiated and maintained via integration of afferent inputs in the supra sacral regions of the central nervous system. Regions of the brain cited to have key roles in the integration of signals include the medial amygdala, MPOA, periaqueductal gray matter, paraventricular nucleus (PVN), and ventral tegmentum among others (16). Studies in animal models, particularly in rats, have been paramount in identifying these key areas of signal integration and control. Electrostimulation of the MPOA, PVN and hippocampus lead to erection and lesions in these areas may prevent erection (17). Marson et al. injected labeled pseudorabies virus into rat corpora cavernosa and traced them to neurons in the spinal cord, brain stem and hypothalamus (18). Stimulation of the rat dorsal nerve led to increased firing in the MPOA not found elsewhere (19). Axonal tracing in animals have shows direct projections from the hypothalamus to the lumbosacral autonomic erection centers. Oxytocin and vasopressin have been identified as central neurotransmitters within the hypothalamic nuclei and may have a role in penile erection (17). These signaling studies identifying key areas of erectile response integration may explain how ED is associated with cerebrovascular accident (CVA), Parkinson’s, epilepsy and MS.
Levitra is available in two strengths: 10 mg and 20 mg. It is not necessary to take it on an empty stomach. Levitra should be started at low dose in men taking certain medications called CYP3A4 inhibitors (ketoconazole, medications for HIV, and clarithromycin) and should be not be used in individuals with a known heart problem called prolonged QT interval or with medications that prolong the QT interval.
The role of the endothelium in ED has been noted for a number of years and the overlapping of ED and other conditions, especially coronary heart disease, CVD, affecting endothelial function/dysfunction, is clearly present. The endothelial cell is now known to affect vascular tone and impact the process of atherosclerosis, and impacting ED, CVD and peripheral vascular disease.16
3. An intact, anatomically correct penis; 25% of impotence may be psychologic or 'partner-specific', 25% has an organic component and 50% of impotence is organic in nature; in organic impotence, nocturnal penile tumescence is absent Management-surgical Microvascular surgery to bypass occluded vessels–most effective in younger ♂, penile prosthesis Management-medical Combined therapy with phentolamine and papaverine–self-injected by the Pt, wielding an erection of 1 hr's duration is useful for arterial, neurologic, psychogenic impotence; other therapies–zinc, bromocriptine–Parlodel, isoxsuprine-Vasodilan, Voxsuprine, nitroglycerine, yohimbine–Yocon, Yohimex Etiology Smoking, CAD, HTN, DM, medications–hypoglycemic agents, vasodilators, cardiac drugs, antihypertensives, anger and depression; it is inversely correlated to dehydroepiandrosterone, HDL-C, and an index of dominant personality Primary impotence Complete absence of successful sexual coupling Secondary impotence Priapism, penile plaques, Peyronie's disease; drugs linked to impotence: antihypertensives–eg, methyldopa, guanethidine, reserpine, clonidine, due to ↓ BP, antidepressants–eg, phenelzine, isocarboxazide, amitriptyline–causing altered moods and decreased libido, tranquilizers–eg, chlordiazepoxide and lorazepam, and the muscle-relaxing diazepam, cimetidine, which ↑ prolactin, and is associated with impotence and loss of libido. Cf Infertility, Orgasmic dysfunction.
• Medications: About 25 percent of ED cases are caused by drugs. Many medications, including common medicines prescribed for diabetes and its complications, can cause ED. The most common offenders are blood pressure drugs, antihistamines, antidepressants, tranquilizers, appetite suppressants, and cimetidine (an ulcer drug). In addition, over-the-counter medications, including certain eye drops and nose drops, have been associated with ED. That does not mean you should stop taking these medications! Rather, you should discuss them with your doctor to determine whether a different dosage, an alternate medicine, or additional treatments will resolve the ED.
Conditions that may be associated with ED include diabetes, [25, 26, 27] hypertension, [28] , and CAD, as well as neurologic disorders, endocrinopathies, benign prostatic hyperplasia, [29] , sleep apnea [30] , COPD, [31] and depression (see Table 1 below). [32, 33, 34, 35] In fact, almost any disease may affect erectile function by altering the nervous, vascular, or hormonal systems. Various diseases may produce changes in the smooth muscle tissue of the corpora cavernosa or influence the patient’s psychological mood and behavior.
Caution is recommended regarding the use of PDE-5 inhibitors and alpha-blockers (for example, Hytrin, Cardura, Uroxatral, Flomax, Rapaflo), medications commonly used to treat benign prostate enlargement (BPH). The combination of these medications can cause lowering of the blood pressure. Stable use of one therapy should occur prior to the addition of the other therapy, which should start at a low dose.
The FDA recommends that men follow general precautions before taking a medication for ED. Men who are taking medications that contain nitrates, such as nitroglycerin, should NOT use these medications. Taking nitrates with one of these medications can lower blood pressure too much. In addition, men who take tadalafil or vardenfil should use alpha blockers with care and only as instructed by their physician, as they could result in hypotension (abnormally low blood pressure). Experts recommend that men have a complete medical history and physical examination to determine the cause of ED. Men should tell their doctor about all the medications they are taking, including over-the-counter medications.
Other treatment options such as penile self-injection therapy, external vacuum pumps and the medicated urethral system for erection are in rare occasions an effective long-term treatment. Only a very small percentage of men will continue with these treatments as evidenced by a very high drop out rate and a very low refill rate. These treatments require extensive planning which interferes with spontaneity. This may be the reason why the refill rate is so low and the drop out of treatment so high.  
Erections are initiated and maintained via integration of afferent inputs in the supra sacral regions of the central nervous system. Regions of the brain cited to have key roles in the integration of signals include the medial amygdala, MPOA, periaqueductal gray matter, paraventricular nucleus (PVN), and ventral tegmentum among others (16). Studies in animal models, particularly in rats, have been paramount in identifying these key areas of signal integration and control. Electrostimulation of the MPOA, PVN and hippocampus lead to erection and lesions in these areas may prevent erection (17). Marson et al. injected labeled pseudorabies virus into rat corpora cavernosa and traced them to neurons in the spinal cord, brain stem and hypothalamus (18). Stimulation of the rat dorsal nerve led to increased firing in the MPOA not found elsewhere (19). Axonal tracing in animals have shows direct projections from the hypothalamus to the lumbosacral autonomic erection centers. Oxytocin and vasopressin have been identified as central neurotransmitters within the hypothalamic nuclei and may have a role in penile erection (17). These signaling studies identifying key areas of erectile response integration may explain how ED is associated with cerebrovascular accident (CVA), Parkinson’s, epilepsy and MS.
SD in MS can be classified into three categories. Primary SD is due directly due to MS-related neurological deficits, secondary SD is related to physical impairments and symptoms or drugs used for MS treatment, and tertiary SD is due to the psychological, social and cultural problems attributed to MS (38). These classifications are important, and underscore the importance of addressing all the issues leading to SD not just the neurologic impairment.
Cavernosography measurement of the vascular pressure in the corpus cavernosum. Saline is infused under pressure into the corpus cavernosum with a butterfly needle, and the flow rate needed to maintain an erection indicates the degree of venous leakage. The leaking veins responsible may be visualized by infusing a mixture of saline and x-ray contrast medium and performing a cavernosogram.[21] In Digital Subtraction Angiography (DSA), the images are acquired digitally.
The penis contains three cylinders, the two corpora cavernosa, which are on the top of the penis (see figure 1 below). These two cylinders are involved in erections. The third cylinder contains the urethra, the tube that the urine and ejaculate passes through, runs along the underside of the penis. The corpus spongiosum surrounds the urethra. Spongy tissue that has muscles, fibrous tissues, veins, and arteries within it makes up the corpora cavernosa. The inside of the corpora cavernosa is like a sponge, with potential spaces that can fill with blood and distend (known as sinusoids). A layer of tissue that is like Saran Wrap, called the tunica albuginea, surrounds the corpora. Veins located just under the tunica albuginea drain blood out of the penis.

Monitoring erections that occur during sleep (nocturnal penile tumescence) can help you and your doctor to understand if the erectile dysfunction is due to psychological or physical causes. The nocturnal penile tumescence test is a study to evaluate erections at night. Normally men have three to five erections per eight hours of sleep. The test can be performed at home or in a sleep lab. The most accurate way to perform the test involves a special device that is connected to two rings. The rings are placed around the penis, one at the tip of the penis and the other at the bottom (base) of the penis. The device records how many erections occur, how long they last, and how rigid they are. The test is limited in that it does not assess the ability to penetrate.


Sildenafil has been previously suggested as a treatment option for ED in men with epilepsy (77,78). However, Matos et al. warned that PDE5i are potentially pro-convulsant and should be used with great caution in men with epilepsy (79). Animal studies in rat and mice overwhelmingly suggest PDE5i can reduce seizure threshold. In human trials, seizures were rare but reported. PDE5i exerted their proconvulsive effect by lower seizure threshold possibly by worsening sleep or obstructive sleep apnea, causing cardiovascular changes, or leading to EEG changes specifically with tadalafil use.

A vacuum constriction device (left) is a cylinder that is placed over the penis. The air is pumped out of the cylinder, which draws blood into the penis and causes an erection. The erection is maintained by slipping a band off of the base of the cylinder and onto the base of the penis. The band can stay in place for up to 30 minutes. The vacuum device can be safely used to treat most causes of erectile failure. Lack of spontaneity, discomfort, and cumbersomeness of the device seem to be the biggest concerns of patients.
Malleable implants usually consist of paired rods, inserted surgically into each of the corpora cavernosa. The rods are stiff, and to have an erection, one bends them up and then when finished with intercourse one bends them down. They do not change in length or width. The malleable implants are the least mechanical and thus have the lowest risk of malfunction. However, also have the least "normal appearance."
Do erectile dysfunction exercises help? Many people have erectile dysfunction (ED), but it is often possible to reverse this with exercises to strengthen muscles in the area. These include pelvic floor exercises. ED can often be due to lifestyle factors including obesity and low physical activity levels. Learn more about exercises for ED here. Read now
Years ago, the standard treatment for impotence was an implantable penile prosthesis or long-term psychotherapy. Although physical causes are now more readily diagnosed and treated, individual or marital counseling is still an effective treatment for impotence when emotional factors play a role. Fortunately, other approaches are now available to treat the physical causes of impotence.
*all photos are models and not actual patients.If you are interested in a prescription product, Hims will assist in setting up a visit for you with an independent physician who will evaluate whether or not you are an appropriate candidate for the prescription product and if appropriate, may write you a prescription for the product which you can fill at the pharmacy of your choice.
Conditions associated with reduced nerve and endothelium function (eg, aging, hypertension, smoking, hypercholesterolemia, and diabetes) alter the balance between contraction and relaxation factors (see Pathophysiology). These conditions cause circulatory and structural changes in penile tissues, resulting in arterial insufficiency and defective smooth muscle relaxation. In some patients, sexual dysfunction may be the presenting symptom of these disorders.
Erections are neurovascular events, meaning that nerves and blood vessels (arteries and veins) are involved in the process of an erection and all must work properly to develop a hard erection that lasts long enough. Erection begins with sexual stimulation. Sexual stimulation can be tactile (for example, by a partner touching the penis or by masturbation) or mental (for example, by having sexual fantasies, viewing porn). Sexual stimulation or sexual arousal causes the nerves going to the penis to release a chemical, nitric oxide. Nitric oxide increases the production of another chemical, cyclic GMP (cGMP), in the muscle of the corpora cavernosa. The cGMP causes the muscles of the corpora cavernosa to relax, and this allows more blood to flow into the penis. The incoming blood fills the corpora cavernosa, making the penis expand.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Parasympathetic pathways originate from the intermediolateral cell columns of the 2nd, 3rd and 4th sacral spinal cord segments. Preganglionic fibers pass through the pelvic plexus where they coalesce with sympathetic fibers from the superior hypogastric plexus. The cavernous nerves that innervate the penis arise from the portion of the pelvic plexus. The pelvic plexus also contains nerves that innervate the rectum, bladder and urinary sphincter and the nerve projections can be damaged during radical excision of the bladder, prostate and rectum, leading to iatrogenic ED (4).
Recently, the US Food and Drug Administration (FDA) has issued a safety announcement regarding TRT. In part it reads ‘The benefit and safety of these medications have not been established. We are also requiring these manufacturers to add information to the labeling about a possible increased risk of heart attacks and strokes in patients taking testosterone.’37
When we say it’s a barometer of men’s health, it’s a signal. It’s an indicator that things may be right or not. And so when a man develops an erectile problem– and we’re talking about something that is occurring over time. It’s not something that just occurred overnight. When it occurs overnight, it’s more often than not a psychogenic, an anxiety reaction.
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