It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge. A significant proportion of men who have no sexual dysfunction nonetheless do not have regular nocturnal erections.

Impotence can have emotional causes but most often it is due to a physical problem. The physical causes of impotence include diseases (such as diabetes and hypertension), injuries (such as from prostate surgery), side-effects of drugs (such as the protease inhibitors used in HIV therapy), and disorders (such as atherosclerosis) that impair blood flow in the penis. Impotence is treatable in all age groups. Treatments include psychotherapy, vacuum devices, surgery and, most often today, drug therapy.
For some patients with an established diagnosis of testicular failure (hypogonadism), androgen replacement therapy may sometimes be effective in improving erectile function. A trial of androgen replacement may be worthwhile in men with low serum testosterone levels if there are no other contraindications. In contrast, for men who have normal testosterone levels, androgen therapy is inappropriate and may carry significant health risks, especially in the situation of unrecognized prostate cancer. If androgen therapy is indicated, it should be given in the form of intramuscular injections of testosterone enanthate or cypionate. Oral androgens, as currently available, are not indicated. For men with hyperprolactinemia, bromocriptine therapy often is effective in normalizing the prolactin level and improving sexual function. A wide variety of other substances taken either orally or topically have been suggested to be effective in treating erectile dysfunction. Most of these have not been subjected to rigorous clinical studies and are not approved for this use by the Food and Drug Administration (FDA). Their use should therefore be discouraged until further evidence in support of their efficacy and indicative of their safety is available.
Erectile dysfunction can be effectively treated with a variety of methods. Many patients and health care providers are unaware of these treatments, and the dysfunction thus often remains untreated, compounded by its psychological impact. Concurrent with the increase in the availability of effective treatment methods has been increased availability of new diagnostic procedures that may help in the selection of an effective, cause-specific treatment. This conference was designed to explore these issues and to define the state of the art.
Only a small proportion of cases of erectile dysfunction are caused by hormone abnormalities. The most frequent hormone abnormality is a reduced level of the male sex hormone testosterone required to get an erection which can be restored by appropriate hormone replacement. It's unwise to take testosterone preparations unless you've had tests that confirm a deficiency.
To start with, ED is NOT in your head. You can’t simply will yourself to get an erection, no matter how much you try. Studies show over 80% of ED cases are caused by a treatable physical disorder. Diseases such as diabetes, high blood pressure, and high cholesterol are common causes. Even a perfectly healthy man can develop ED after a brain or spinal cord injury. ED can be a side effect of certain medications, too.  Read more on our Causes of ED page.

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 erectile dysfunction within medicine is covered by andrology, a sub-field within urology. Research indicates that erectile dysfunction is common, and it is suggested that approximately 40% of males with erectile dysfunction or impotence, at least occasionally.[35] The condition is also on occasion called phallic impotence.[36] Its antonym or opposite condition is priapism.[37][38]
The recommended starting dose of vardenafil is 10 mg taken orally approximately one hour before sexual activity. A doctor may adjust the dose higher or lower depending on efficacy and side effects. The maximum recommended dose is 20 mg, and the maximum recommended dosing frequency is no more than once per day. Patients can take vardenafil with or without food. As with sildenafil, for vardenafil to be effective, sexual stimulation must occur.

Erection is a vascular event. The penis becomes rigid when blood flow to the corpora cavernosa increases sixfold and venous outflow is physiologically impeded. Penile perfusion is governed by three organ systems—the neurologic, circulatory, and endocrinologic systems—each necessary for potency. The neurologic system accounts for vasodilation and venoconstriction of the corporal blood vessels so that blood is shunted to the erectile tissues; the circulatory system provides adequate blood flow to the hypogastric-cavernous bed, a distal branch off the internal iliac vessels; and the endocrine system, mediated by testosterone, plays a permissive role through mechanisms that have yet to be elucidated.


The prostaglandin E1 is contained in a small suppository located at the tip of an applicator. You should urinate first as this lubricates the urethra and makes it easier to insert the applicator into the tip of the urethra (urethral meatus, the opening at the tip of the penis that urine passes through). A patient can release the suppository into urethra by gently wiggling the applicator and pressing the button at the end. Rubbing the penis allows the suppository to dissolve, and the prostaglandin is absorbed through the tissue of the urethra into the penis. It takes 15 to 30 minutes for this occur. Once into the penis, the prostaglandin causes increased blood flow into the penis. The prostaglandin can be present in the ejaculate, and thus doctors recommend that men use a condom when having intercourse with a pregnant partner. Men may need to use a condom if vaginal irritation occurs in female partner.


Prevention of some of the causes that contribute to the development of erectile dysfunction can decrease the chances of developing the problem. For example, if a person decreases their chances of developing diabetes, heart disease, and hypertension, they will decrease their chances of developing erectile dysfunction. Other things like stopping smoking, eating a healthy diet (heart healthy with adequate vitamin intake), and exercising daily may reduce a person's risk.
The general medical history is important in identifying specific risk factors that may account for or contribute to the patient's erectile dysfunction. These include vascular risk factors such as hypertension, diabetes, smoking, coronary artery disease, peripheral vascular disorders, pelvic trauma or surgery, and blood lipid abnormalities. Decreased sexual desire or history suggesting a hypogonadal state could indicate a primary endocrine disorder. Neurologic causes may include a history of diabetes mellitus or alcoholism with associated peripheral neuropathy. Neurologic disorders such as multiple sclerosis, spinal injury, or cerebrovascular accidents are often obvious or well defined prior to presentation. It is essential to obtain a detailed medication and illicit drug history since an estimated 25 percent of cases of erectile dysfunction may be attributable to medications for other conditions. Past medical history can reveal important causes of erectile dysfunction, including radical pelvic surgery, radiation therapy, Peyronie's disease, penile or pelvic trauma, prostatitis, priapism, or voiding dysfunction. Information regarding prior evaluation or treatment for "impotence" should be obtained. A detailed sexual history, including current sexual techniques, is important in the general history obtained. It is also important to determine if there have been previous psychiatric illnesses such as depression or neuroses.
For the past few months I’ve been dating a lovely man but our relationship is at risk because he can’t get it up. He says he fancies me and always seems turned on. Sometimes he gets hard - but when we try for sex he loses his erection. On the few occasions he has got hard, he doesn’t orgasm. I’ve always been a very sexual person and would like a lot of sex. We’re hardly having any. I find it difficult to orgasm even if he tries other things because I keep thinking. Why can’t he have proper sex with me?

Name of DrugWhen to TakeDoseDietary RestrictionsViagraTake between 30 and 60 minutes (and up to 4 hours) before sex; works for about 4 hoursRecommended dose for most men is 50mgs; after that, dosage may go to as high as 100mg, or as low as 25mg, which may be prescribed for men over 65.Quickly absorbed by the body, less effective after a high-fat meal, and best taken on an empty stomach.Name of DrugWhen to TakeDoseDietary RestrictionsLevitraTake 1 hour before sex; works for 4 to 5 hours, and may be slightly more effective than ViagraStarting dose for most men is 10mgs a day, but men over 65 often start on the 5mg pill.Can be taken with or without food, although slightly less effective after a high-fat meal.  Avoid anything containing grapefruit juice; it may make side effects worse.Name of DrugWhen to TakeDoseDietary RestrictionsCialisComes in two forms. The daily pill stays effective in between doses, but may take 4 to 5 days before it begins working. The “weekender” version of Cialis can start working in as little as 30 minutes for men who take the highest dose of the drug (20mgs); it stays effective in the body for up for 36 hours.Daily pill comes in both a 2.5mg and 5mg tablet; most men start with the lower dose. The use-as-needed, “weekender” pill comes in 5, 10 and 20mg strengths; recommended starting dose is 10mg,Can be taken with or without food.   Avoid heavy drinking (5 glasses of wine or 5 shots of whiskey); when combined with Cialis, it can lead to headaches, dizziness, an increase in heart rate, and a drop in blood pressure.Name of DrugWhen to TakeDoseDietary RestrictionsStaxyn Take 1 hour before sex, although many men report erections in 20 to 30 minutes.  Because Staxyn comes in a sleek black package and is taken as a rapidly dissolving tablet (without water), some men think of it as a more discrete way to treat ED.Comes in 10mg tablets; do not take more than 1 a day.Avoid taking it with any kind of liquid. Should be placed directly on the tongue and allowed to dissolve without chewing.Name of DrugWhen to TakeDoseDietary RestrictionsStendraPrescribing information now recommends taking it 30 minutes before sex. Some men, however, report results in as little as 10 to 12 minutes, depending on the dose. Because of these findings, Auxilium Pharmaceuticals, the Chesterbrook, Pa., company that has U.S. marketing rights to the drug, has asked the FDA to revise the prescribing information.Starting dose is 100mgs for most men, but the 50mg tablet is recommended for men taking alpha-blocker drugs, like those used for high blood pressure and prostate problems.May be taken with or without food, and with a moderate amount of alcohol (3 drinks).   Drinking more than that can increase the chances of side effects like rapid heart rate, low blood pressure, dizziness and headaches.Name of DrugWhen to TakeDoseDietary RestrictionsPenile injections & the MUSE suppositoryTake 5 to 10 minutes before planning to have sex; erections last for 30 to 60 minutes.MUSE comes in 4 dosage strengths; most men start at 125mgs. Avoid taking more than twice within a 24-hour period.N/A
Men with a rare heart condition known as long QT syndrome should not take vardenafil since this may lead to abnormal heart rhythms. The QT interval is the time it takes for the heart's muscle to recover after it has contracted. An electrocardiogram (EKG) measures the QT interval. Some people have longer than normal QT intervals, and they may develop potentially life-threatening abnormal heart rhythms, especially when given certain medications. Men with a family history of long QT syndrome should not take vardenafil, as it is possible to inherit long QT syndrome. Furthermore, vardenafil is not recommended for men who are taking medications that can affect the QT interval such as quinidine (Quinaglute, Quinidex), procainamide (Pronestyl, Procan-SR, Procanbid), amiodarone (Cordarone), and sotalol (Betapace).

Currently, placement of a penile prosthesis is the most common surgical procedure performed for erectile dysfunction. Penile prosthesis placement is typically reserved for men who have tried and failed (either from efficacy or tolerability) or have contraindications to other forms of therapy including PDE5 inhibitors, intraurethral alprostadil, and injection therapy.

Heart disease isn't the only risk. ED is also a predictor of stroke, because when the arteries are narrowed there is more chance of a blood clot, which can spread to the brain. It is also a common complication of diabetes. But embarrassment stops people seeking help, says Jackson. "We need to encourage men to talk to their spouses about this problem, instead of making an excuse to avoid sex.
The symptoms of erectile dysfunction include difficulty achieving an erection, trouble maintaining an erection, and a reduced interest in sex. Because male sexual arousal is a fairly complex process, it can sometimes be difficult to identify a specific cause. Arousal starts in the brain but it also involves the nerves, muscles, and blood vessels and can be impacted by hormones and emotions. If a problem develops with any of these things, erectile dysfunction could be the consequence.
Having learned a great deal more about erectile dysfunction including its risk factors and causes, you should be equipped to assess your own erectile function. If you have experienced erectile issues or you have some of the risk factors mentioned above, it may be worth making a trip to your doctor’s office. If you choose to seek help, give your doctor as much information as you can about your symptoms including their frequency and severity as well as the onset. With your doctor’s help, you can determine the best course of treatment to restore sexual function.
Does drinking water improve erectile dysfunction? Erectile dysfunction or ED is a common concern for men. Everyday factors, such as hydration levels, may affect a person's ability to get or maintain an erection. Drinking water may, therefore, help some men with ED. In this article, learn about the link between hydration and ED, and other factors that can cause ED. Read now
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