ED usually has something physical behind it, particularly in older men. But psychological factors can be a factor in many cases of ED. Experts say stress, depression, poor self-esteem, and performance anxiety can short-circuit the process that leads to an erection. These factors can also make the problem worse in men whose ED stems from something physical.
All NOS subtypes produce NO, but each may play a different biologic role in various tissues. nNOS and eNOS are considered constitutive forms because they share biochemical features: They are calcium-dependent, they require calmodulin and reduced nicotinamide adenine dinucleotide phosphate for catalytic activity, and they are competitively inhibited by arginine derivatives. nNOS is involved in the regulation of neurotransmission, and eNOS is involved in the regulation of blood flow.
Dr. Liou says that some men come to him after getting a prescription from their primary care doctors, claiming that the drug doesn't work. Sometimes it's because they used it incorrectly. "The biggest misconception is that these drugs are an on/off switch for erections," Dr. Liou says. But the drugs don't work well without sexual stimulation. "During that time, you need to be with your partner and have foreplay," Dr. Liou says. "Don't take it, do the taxes or the dishes, and then meet at the bedroom thinking you'll be ready to go. It's not like that."
The inflatable type of device consists of cylinders that are implanted in the corpora cavernosa, a fluid reservoir implanted in the abdomen, and a pump placed in the scrotum. The man squeezes the pump to move fluid into the cylinders and cause them to become rigid. (He reverses the process by squeezing the pump again.) While these devices allow for intermittent erections, they have a slightly higher malfunction rate than the silicon rods.
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.
There are hundreds of medications that have the side effect of ED and/or decreased libido. Examples of drugs implicated as a cause of ED include hydrochlorothiazides and beta-blocking agents. Medications used to treat depression, particularly the SSRIs such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Prozac Weekly, Sarafem), fluvoxamine (Luvox, Luvox CR), paroxetine (Paxil, Paxil CR, Pexeva) and sertraline (Zoloft), may also contribute to ED.9 Bupropion (Wellbutrin) which has a predominant effect on blocking the reuptake of dopamine is an antidepressant with lower incidence of ED.10 The side effects of 5ARIs occurring in fewer than 5% of patients can include gynaecomastia, ED, loss of libido and ejaculatory dysfunction.11
About six months ago, I was talking to another guy (I have a boyfriend) online, and I ended up sending him a topless pic of me. I have been with my man for almost five years, and I feel so guilty and stupid for doing it — not only because I'm dating someone, but also because it's a stupid thing to do anyway. I love my man so much, and I don't know what to do.
Another study compared the response of surgically and medically castrated rabbits to vardenafil with that of control rabbits.  Castrated rabbits did not respond to vardenafil, whereas noncastrated rabbits did respond appropriately. This result suggests that a minimum amount of testosterone is necessary for PDE5 inhibitors to produce an erection.
You're right that this should be a last resort, but Paduch also agrees that sometimes a little confidence can help you get back on track. The thing is, you should only take an ED medicine if it's prescribed by your doctor (otherwise you'll miss out on the important medical info you should know before you take it). Another option is an l-arginine supplement, which can increase nitric oxide and blood flow.
Stiffy Solution: Obviously, no one should ever go off a prescribed med without consulting with a doctor. But there are erection-friendly alternatives to nearly every daisy-wilting medicine listed above. And your dude shouldn't let embarrassment keep him from talking to his GP about this — doctors are well aware that erectile difficulties are a possible side effect for all of these medicines; they just don't know which patients will experience what side effects, so they're waiting for you, the patient, to bring it up.
The most common inflatable prosthesis is the three-piece penile prosthesis. It is composed of paired cylinders, which doctors surgically insert inside the penis. Patients can expand the cylinders using pressurized fluid (see figure 3). Tubes connect the cylinders to a fluid reservoir and pump, which doctors also surgically implant. The reservoir is usually in the pelvis. A doctor places the pump in the scrotum. By pressing on the pump, sterile fluid transfers from the reservoir into the cylinders in the penis. An erection is produced primarily by expansion of the width of the penis, however, one model can increase in length a small amount also. Lock-out valves in the tubing prevent the fluid from leaving the cylinder until a release valve is pressed. By pressing the relief valve and gently squeezing the penis, the fluid within the cylinders transfers back into the reservoir.
It is estimated that up to 20 million American men frequently suffer from impotence and that it strikes up to half of all men between the ages of 40 and 70. Doctors used to think that most cases of impotence were psychological in origin, but they now recognize that, at least in older men, physical causes may play a primary role in 60% or more of all cases. In men over the age of 60, the leading cause is atherosclerosis, or narrowing of the arteries, which can restrict the flow of blood to the penis. Injury or disease of the connective tissue, such as Peyronie's disease, may prevent the corpora cavernosa from completely expanding. Damage to the nerves of the penis, from certain types of surgery or neurological conditions, such as Parkinson's disease or multiple sclerosis, may also cause impotence. Men with diabetes are especially at risk for impotence because of their high risk of both atherosclerosis and a nerve disease called diabetic neuropathy.
Radical prostatectomy for the treatment of prostate cancer poses a significant risk of ED. A number of factors are associated with the chance of preserving erectile function. If both nerves that course on the lateral edges of the prostate can be saved, the chance of maintaining erectile function is reasonable. The odds depend on the age of the patient. Men younger than 60 years have a 75-80% chance of preserving potency, but men older than 70 years have only a 10-15% chance.
Injection of vasodilator substances into the corpora of the penis has provided a new therapeutic technique for a variety of causes of erectile dysfunction. The most effective and well-studied agents are papaverine, phentolamine, and prostaglandin E[sub 1]. These have been used either singly or in combination. Use of these agents occasionally causes priapism (inappropriately persistent erections). This appears to have been seen most commonly with papaverine. Priapism is treated with adrenergic agents, which can cause life-threatening hypertension in patients receiving monoamine oxidase inhibitors. Use of the penile vasodilators also can be problematic in patients who cannot tolerate transient hypotension, those with severe psychiatric disease, those with poor manual dexterity, those with poor vision, and those receiving anticoagulant therapy. Liver function tests should be obtained in those being treated with papaverine alone. Prostaglandin E[sub 1] can be used together with papaverine and phentolamine to decrease the incidence of side effects such as pain, penile corporal fibrosis, fibrotic nodules, hypotension, and priapism. Further study of the efficacy of multitherapy versus monotherapy and of the relative complications and safety of each approach is indicated. Although these agents have not received FDA approval for this indication, they are in widespread clinical use. Patients treated with these agents should give full informed consent. There is a high rate of patient dropout, often early in the treatment. Whether this is related to side effects, lack of spontaneity in sexual relations, or general loss of interest is unclear. Patient education and followup support might improve compliance and lessen the dropout rate. However, the reasons for the high dropout rate need to be determined and quantified.
Surgery: If neither drugs nor the vacuum pump works, your doctor may suggest surgery. With surgery, the doctor can place a device in your penis that will cause enough hardness for intercourse. In a few cases, infections may develop after the operation, and the doctor may have to remove the device. Another operation that may help you is rebuilding the blood vessels in the penis to increase blood flow into the penis or decrease blood flow out of the penis. These procedures can help you to get and maintain an erection.
Prostate cancer isn’t considered a cause of ED on its own, but radiation treatments, hormone therapy, and surgery to remove the entire prostate gland can lead to difficulty in getting or keeping an erection. Sometimes erectile dysfunction related to prostate cancer treatment is only temporary, but many guys experience ongoing difficulties that need to be addressed by other means.
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
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.
Maybe your performance issues stem from feelings of discomfort relating to something you've done. Are you having trouble performing because you're feeling uncertain about whether you really love your partner? Or because you feel like you crossed a line in terms of infidelity and now the guilt is tearing you up inside? Maybe your conscience is what's wreaking havoc with your sex.
With sex therapy, your counselor looks at the sexual problems you and your partner are having. Sex therapy works with problems such as performance anxiety, which means that you worry so much about whether you will be able to have sex that you are not able to. It also helps when you have erection problems that are not due to physical or drug problems, or premature ejaculation (you come too quickly). It may help you to reach orgasm or to learn to relax enough to avoid pain during sex. Counseling can help you to adjust to the treatment you and your doctor choose.
Most older men suffer not ED but erection dissatisfaction. Starting around age 50 (often earlier among smokers and/or diabetics), erections change. In some men, the process is gradual, in others, it happens more quickly. Either way, older men lose the ability to raise erections solely from sexual fantasies. Direct fondling of the penis becomes necessary. When erections appear, they rise more slowly and do not become as firm as they were during men’s thirties and forties. And minor distractions may cause wilting—the doorbell or an ambulance siren. These changes alarm many men, who jump to the conclusion that they must have ED. If you can still raise erection durings masturbation, you don’t. What you have is erection dissatisfaction.
The association between low testosterone and ED is not entirely clear. Although these 2 processes certainly overlap in some instances, they are distinct entities. Some 2-21% of men have both hypogonadism and ED; however, it is unclear to what degree treating the former will improve erectile function.  About 35-40% of men with low testosterone see an improvement in their erections with testosterone replacement; however, almost 65% of these men see no improvement. 
2 inability of the adult male to achieve or sustain a penile erection or, less commonly, to ejaculate after achieving an erection. Several forms are recognized. Functional impotence has a psychological basis. Organic impotence includes vasculogenic, neurogenic, endocrinic, and anatomical factors. Anatomical impotence results from physically defective genitalia. Atonic impotence involves disturbed neuromuscular function. Poor health, old or advancing age, drugs, smoking, trauma, and fatigue can induce impotence. Also called erectile dysfunction, impotency. impotent, adj.
Men with physical causes of ED have options, including such medicines as sildenafil (Viagra®), vardenafil (Levitra®), or tadalafil (Cialis®). Men who use nitroglycerin products and those who should avoid sexual activity because of cardiovascular disease shouldn’t take these drugs. Other treatment modalities include use of a vacuum pump or injection of a substance (papaverine) into the penis to increase blood flow to the penis. Men can also have surgery to put a prosthesis into the penis.
In diabetics, impotence that develops acutely in the setting of hyperglycemia and poor metabolic control is usually reversible. This is not true of the slowly progressive impotence of long-standing diabetes that is a manifestation of autonomic neuropathy. Intracavernosal self-injection of vasoactive drugs such as papaverine, which relaxes arteriolar smooth muscle is a promising new approach to treatment that is particularly suited for diabetic patients whose erectile dysfunction is on a neuropathic basis. It also has been used with success in spinal cord patients.
However, in contrast, a recent systematic review of published studies, the authors concluded that overall, the addition of testosterone to PDE-5 inhibitors might benefit patients with ED associated with testosterone levels of less than 300 ng/dL (10.4 nmol/L) who failed monotherapy.  A limitation of existing studies are their heterogeneous nature and methodological drawbacks.
Impotence, also called erectile dysfunction, in general, the inability of a man to achieve or maintain penile erection and hence the inability to participate fully in sexual intercourse. In its broadest sense the term impotence refers to the inability to become sexually aroused; in this sense it can apply to women as well as to men. In common practice, however, the term has traditionally been used to describe only male sexual dysfunctions. Professional sex therapists, while they identify two distinct dysfunctions as forms of impotence, prefer not to use the term impotence per se. Thus, because of its pejorative connotation in lay usage and because of confusion about its definition, the word impotence has been eliminated from the technical vocabulary in favour of the term “erectile dysfunction.”
In a prospective study from the Prostate Cancer Prevention Trial database, Thompson et al reported that men presenting with ED had a significantly higher chance of developing a cardiovascular event over a 7-year follow-up period.  The hazard ratio was 1.45, which is in the range of risk associated with current smoking or a family history of MI.
How soon the drugs start working ranges from 15 to 60 minutes. Neither Viagra nor Levitra will work if you take them after a meal, which blocks their absorption. However, neither Cialis nor Stendra interact with food this way. The onset time determines how soon you can engage in intercourse. Stendra and daily-use Cialis are closest to being an "on demand" erectile drug; using the others requires more planning.
Erections are more complicated than you think. Your brain, nerves, heart, blood vessels, and a whole lot of hormones have to work together perfectly or nothing happens. It’s a lot to ask, and sometimes things break down. And while ED happens to most guys at some point in their lives, erectile dysfunction isn’t something you can just ignore and hope it goes away.