Penile erection is managed by two mechanisms: the reflex erection, which is achieved by directly touching the penile shaft, and the psychogenic erection, which is achieved by erotic or emotional stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic system of the brain. In both cases, an intact neural system is required for a successful and complete erection. Stimulation of the penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. Additionally, adequate levels of testosterone (produced by the testes) and an intact pituitary gland are required for the development of a healthy erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems. Spinal cord injury causes sexual dysfunction including ED. Restriction of blood flow can arise from impaired endothelial function due to the usual causes associated with coronary artery disease, but can also be caused by prolonged exposure to bright light.
To examine what is known about the demographics, etiology, risk factors, pathophysiology, diagnostic assessment, treatments (both generic and cause-specific), and the understanding of their consequences by the public and the medical community, the National Institute of Diabetes and Digestive and Kidney Diseases and the Office of Medical Applications of Research of the National Institutes of Health, in conjunction with the National Institute of Neurological Disorders and Stroke and the National Institute on Aging, convened a consensus development conference on male impotence on December 7-9, 1992. After 1 1/2 days of presentations by experts in the relevant fields involved with male sexual dysfunction and erectile impotence or dysfunction, a consensus panel comprised of representatives from urology, geriatrics, medicine, endocrinology, psychiatry, psychology, nursing, epidemiology, biostatistics, basic sciences, and the public considered the evidence and developed answers to the questions that follow.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.
Thanks for your question, Frightened Turtle! To help answer it, we spoke with Dr. Darius Paduch, urologist and male sexual medicine specialist at New York Presbyterian/Weill Cornell Medical Center, and sex therapist Jenni Skyler, Ph.D., director of The Intimacy Institute for sex and relationship therapy in Boulder, Colorado. Here's what they had to say:
The medications are extremely effective, which is very good. And the medications are, for the most part, extremely well-tolerated. But there are, like with any medications, a potential downside. The one absolute downside to the use of any of these erection what we call PDE5 medications is if a patient is using a nitroglycerin medication. And nitroglycerins are used for heart disease and for angina, for the most part, although there are some recreational uses of nitrites. And that’s important because your blood vessels will dilate and your blood pressure will drop. And that is an absolute contraindication.
As is true in so many medical conditions, lifestyle modifications, considered first-line therapy, can have a salutary effect in ED management, and men should be encouraged to make the necessary changes to the benefit of their sexual function and to their overall health as well. Despite the benefits of behaviour modification, men presenting with ED want the physician to help with measures that can have an immediate impact.
The physical side effects of chemotherapy are usually temporary and resolve within one to two weeks after stopping the chemotherapy. However, chemotherapy agents, such as Ciplatin or Vincristine, may interfere with the nerves that control erection leading to possible impotence. Make sure you discuss potential side effects of cancer chemotherapy with your doctor or healthcare provider.
However, men are affected psychologically when it comes to achieving erections. For instance, if a man is with a woman for the first time, or even before he feels comfortable with her, he may suffer from performance anxiety. In such a situation, his mind and body are both saying yes, but then they become out of sync. The body is then saying yes, but the mind is filled with question. “Will I be able to perform?” “How long will I last?” “Am I big enough to satisfy her?” “Is she looking at that mole on my stomach?” All kinds of questions may be going through a man’s mind upon getting in bed, and these can be distracting, they can lead to self-doubt, and therefore, failure to achieve or maintain an erection.
JP graduated from University of California, Davis with a degree in Human Development. Prior to Lemonaid, JP worked in worker’s compensation case management, ensuring patients avoided permanent disability and adhered to medication guidelines to prevent medication overdose. She also spent time volunteering at pediatric occupational therapy clinics helping differently-abled children. She has a strong interest in mental health advocacy and believes that no matter the circumstance, everyone deserves the best quality of life possible. She joined the Lemonaid mission because she strongly supports the idea that healthcare should be both affordable and easily accessible to everyone. Outside of work, she enjoys DIY projects, anything crafty, live music and spending time with her dogs!
ED is defined as the inability to achieve a full erection or the inability to maintain an erection adequate for sexual intimacy. Other types of sexual dysfunction such as premature ejaculation and low libido may occur; however, the most common and disruptive problem in men is ED. Although most men will experience periodic episodes of ED, these episodes tend to become more frequent with advancing age.
Remember what I said before about how it's not you? Okay, sometimes it is you. But it's not that you're not sexy — it's that for men, as well as women, relationship problems (like fighting all the time, or having clashing expectations about where things are going) can severely mess up your sex drive and ability to become aroused. Which makes sense — if you're spending 90 percent of your time together fighting about whether you're going to move in, switching gears to make 10 percent of your time together into a sexy sex party is pretty damned difficult.
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.
The laboratory results should be discussed with the patient and, if possible, with his sexual partner. This educational process allows a review of the basic aspects of the anatomy and physiology of the sexual response and an explanation of the possible etiology and associated risk factors (eg, smoking and the use of various medications). Treatment options and their benefits and risks should be discussed. This type of dialogue allows the patient and physician to cooperate in developing an optimal management strategy.
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.
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.  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.
The primary nerve fibers to the penis are from the dorsal nerve of the penis, a branch of the pudendal nerve. The cavernosal nerves are a part of the autonomic nervous system and incorporate both sympathetic and parasympathetic fibers. They travel posterolaterally along the prostate and enter the corpora cavernosa and corpus spongiosum to regulate blood flow during erection and detumescence. The dorsal somatic nerves are also branches of the pudendal nerves. They are primarily responsible for penile sensation. 
Several pathways have been described to explain how information travels from the hypothalamus to the sacral autonomic centers. One pathway travels from the dorsomedial hypothalamus through the dorsal and central gray matter, descends to the locus ceruleus, and projects ventrally in the mesencephalic reticular formation. Input from the brain is conveyed through the dorsal spinal columns to the thoracolumbar and sacral autonomic nuclei.
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.
Long-term predictions based on an aging population and an increase in risk factors (eg, hypertension, diabetes, vascular disease, pelvic and prostate surgery, benign prostatic hyperplasia, and lower urinary tract symptoms) suggest a large increase in the number of men with ED. In addition, the prevalence of ED is underestimated because physicians frequently do not question their patients about this disorder.
The 4 ED medicines we prescribe – Generic sildenafil 20 mg, Viagra (also sildenafil), Cialis (Tadalafil), or Levitra (Vardenafil) - are generally safe but shouldn’t be used as recreational drugs. They’re meant to treat a medical condition and can cause serious side effects including but not limited to an erection lasting more than four hours, sudden loss of vision in one or both eyes, and sudden decrease or loss of hearing.
Other hormone levels: Measurement of other hormones beside testosterone (luteinizing hormone [LH], prolactin level, and cortisol level) may provide clues to other underlying causes of testosterone deficiency and erectile problems, such as pituitary disease or adrenal gland abnormalities. Doctors may check thyroid levels in some individuals as both hypothyroidism (low thyroid function) and hyperthyroidism (overactive thyroid function) can contribute to erectile dysfunction.
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?
For younger men, erection problems usually go hand-in-hand with anxiety. It goes something like this. He fancies you and wants to turn you on. But he’s also worried he might not get, or keep, his erection (particularly if he really likes you and/or if this has been a problem in past relationships). These worries mean that when you try and have sex he doesn’t get hard at all, or loses his erection when he tries to penetrate you.
So what do you do? If the guilt is too much, you can tell your boyfriend. It might be the only way to clear your conscience — and hopefully, if you explain the reasons why you did such a boneheaded thing, he'll understand. It will be hard and it may create drama for months to come, but my guess is that you can recover, if he's not a horribly jealous guy.
Although not indicated for routine use, nocturnal penile tumescence (NPT) testing may be useful in the patient who reports a complete absence of erections (exclusive of nocturnal "sleep" erections) or when a primary psychogenic etiology is suspected. Such testing should be performed by those with expertise and knowledge of its interpretation, pitfalls, and usefulness. Various methods and devices are available for the evaluation of nocturnal penile tumescence, but their clinical usefulness is restricted by limitations of diagnostic accuracy and availability of normative data. Further study regarding standardization of NPT testing and its general applicability is indicated.
"One couple came to see me, and when I asked the man how long he'd had erectile dysfunction, he told me it had been happening for five years. His wife looked at him and said: 'But this is the first I've heard of this.'" He adds that Viagra-type drugs can mask the problem, and many men still buy them online to avoid talking to their doctor about their difficulties in the bedroom. As a result, their risk of heart attack is never picked up.
A vacuum erection device helps draw blood into the penis by applying negative pressure. This type of device is sometimes referred to as penis pump and may be used just prior to sexual intercourse. Several types of FDA approved vacuum therapy devices are available with a doctor's prescription. When pharmacological methods fail, a purpose-designed external vacuum pump can be used to attain erection, with a separate compression ring fitted to the penis to maintain it. These pumps should be distinguished from other penis pumps (supplied without compression rings) which, rather than being used for temporary treatment of impotence, are claimed to increase penis length if used frequently, or vibrate as an aid to masturbation. More drastically, inflatable or rigid penile implants may be fitted surgically.
Psychological processes such as depression, anxiety, and relationship problems can impair erectile functioning by reducing erotic focus or otherwise reducing awareness of sensory experience. This may lead to inability to initiate or maintain an erection. Etiologic factors for erectile disorders may be categorized as neurogenic, vasculogenic, or psychogenic, but they most commonly appear to derive from problems in all three areas acting in concert.
My husband and I are both 64. My husband has the same problems with erections. Viagra doesnt work. We even tried canabis. Not much happened. I think he just doesn't care much. It just makes me feel lonely and kind of sad. I am just sad and depressed, and this doesn't help. I suggested watching some soft porn. Really thought that might help but not much interest there either. I guess it's just me.
Another approach is vacuum therapy. The man inserts his penis into a clear plastic cylinder and uses a pump to force air out of the cylinder. This forms a partial vacuum around the penis, which helps to draw blood into the corpora cavernosa. The man then places a special ring over the base of the penis to trap the blood inside it. The only side effect with this type of treatment is occasional bruising if the vacuum is left on too long.
Impotence, or erectile dysfunction, is the inability of a male to attain and keep an erection sufficiently firm to engage in or complete sexual intercourse. Although it is more common in older men, impotence can occur at any age. Impotence is not a normal consequence of aging. About 70% of erectile dysfunction is due to diseases such as diabetes and atherosclerosis, another 10% to 20% is due to psychological factors, and the remaining percentage is related to medications, lifestyle factors, and injury (Source: NIDDK).
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.
You get to decide what is normal for you. That might include him still experiencing pleasure from you touching his penis even if he’s not hard. Some men can still orgasm without an erection. Or he may prefer not to have any touching while he is dealing with his erection problems. It is okay for you to orgasm even if he doesn’t. Reading about what might bring you pleasure, or considering how you think about sex can make this something enjoyable to explore together.
Don’t give up or blame yourself - you shouldn’t assume that your situation is impossible to improve or that your partner is disappointed in you. Studies show as long as you don’t stop trying to engage your partner sexually, they will still respond positively. If you communicate and stay positive you can work with your partner to get the result you’re looking for.
In their extensive review, Bassil and coworkers summarise the benefits and risks, with benefits such as improvement of sexual function, bone density, muscle strength, cognition and overall improvement in quality of life. Among the risks that have been suggested include erythrocytosis, liver toxicity, worsening of sleep apnoea and cardiac function, possibly increasing symptoms of benign prostatic hyperplasia (BPH). They also note that although a possibility of stimulation of prostate cancer has been hypothesised, no scientific or clinical evidence exists to this possible risk.38
ED can be caused by either physical and/or psychological factors like stress, anxiety, or depression. Importantly, ED can be the first sign of heart or other health conditions, including cardiovascular disease and diabetes. We offer the optional order of a lab test to investigate whether you might have more serious underlying health problems. Our doctors can order investigative labs in all the states we operate in apart from AZ, NY, NJ and RI. You’ll need to go to a Quest Diagnostics center to have these tests done. When we get the test results back, we can help you understand what they mean.
Uncooperative boners might be related to low testosterone, which could be caused by anything from being overweight or stressed to having a chronic health condition, says Paduch. And in men who have taken anabolic steroids, it's not uncommon for them to end up suppressing their natural testosterone production. If you abuse it over a long period of time, you can really mess with your natural testosterone levels, as well as your fertility and erectile function, he says.
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.
If a man's arteries become blocked with cholesterol – as a result of genetics, and/or lifestyle factors such as smoking, a poor diet and lack of exercise – it will affect the vessels all over his body. The arteries supplying the penis are relatively small, just 1-2mm wide, and so they become blocked more quickly than others. The blood flow to the area is reduced, meaning erections become more difficult.
The dorsal artery provides for engorgement of the glans during erection, whereas the bulbourethral artery supplies the bulb and the corpus spongiosum. The cavernous artery effects tumescence of the corpus cavernosum and thus is principally responsible for erection. The cavernous artery gives off many helicine arteries, which supply the trabecular erectile tissue and the sinusoids. These helicine arteries are contracted and tortuous in the flaccid state and become dilated and straight during erection. 
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.