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.
In a prospective, multicenter, single-armed study of ED patients who exhibited a suboptimal response to PDE5 inhibitors, the investigators found that percutaneous implantation of zotarolimus-eluting stents in focal atherosclerotic lesions was both safe and feasible and was associated with clinically meaningful improvement on subjective and objective measures of erectile function. 
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.”
One must be very careful using both PDE5 inhibitors and medications commonly used to treat an enlarged prostate, alpha-blockers (for example, tamsulosin [Flomax], terazosin [Hytrin]). It is recommended that one be on a stable dose of the alpha-blocker prior to starting a PDE5 inhibitor and that one start on a low dose of the PDE5 inhibitor and increase as tolerated and needed to treat the erectile dysfunction. Similarly, if you are on a PDE5 inhibitor and your doctor recommends that you start an alpha-blocker for your prostate, you should start at a low dose and increase as tolerated and needed to treat your prostate symptoms.
Sexual stimulation causes the release of neurotransmitters from cavernosal nerve endings and relaxation factors from endothelial cells lining the sinusoids. NOS produces NO from L-arginine, and this, in turn, produces other muscle-relaxing chemicals, such as cGMP and cyclic adenosine monophosphate (cAMP), which work via calcium channel and protein kinase mechanisms (see the image below). This results in the relaxation of smooth muscle in the arteries and arterioles that supply the erectile tissue, producing a dramatic increase in penile blood flow.
Certain feelings can interfere with normal sexual function, including feeling nervous about or self-conscious about sex, feeling stressed either at home or at work, or feeling troubled in your current sexual relationship. In these cases, treatment incorporating psychological counseling with you and your sexual partner may be successful. One episode of failure, regardless of cause, may propagate further psychological distress, leading to further erectile failure.
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.
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.
The physical examination can reveal clues for physical causes of erectile dysfunction. A doctor will perform an assessment of BMI and waist circumference to evaluate for abdominal obesity. A genital examination is part of the evaluation of erectile dysfunction. The examination will focus on the penis and testes. The doctor will ask you about penile curvature and will examine the penis to see if there are any plaques (hard areas) palpable. The doctor will examine the testes to make sure they are in the proper location in the scrotum and are normal in size. Small testicles, lack of facial hair, and enlarged breasts (gynecomastia) can point to hormonal problems such as hypogonadism with low testosterone levels. A health care provider may check pulses in your groin and feet to determine if there is a suggestion of hardening of the arteries that could also affect the arteries to the penis.
A study published in May 2014 in The Journal of Sexual Medicine found that some men can reverse erectile dysfunction with healthy lifestyle changes, such as exercise, weight loss, a varied diet, and good sleep. The Australian researchers also showed that even if erectile dysfunction medication is required, it's likely to be more effective if you implement these healthy lifestyle changes.
The American Urological Association Guideline on the Management of ED states oral PDE5i are considered first line therapy for the treatment of ED, unless contraindicated (57). Sildenafil, the first oral PDE5i, was introduced in 1998 and has revolutionized ED therapy due to its broad applicability, effectiveness and safety profile. PDE5i work by preventing hydrolysis of cGMP by the PDE5 enzyme in the smooth muscle of the corpora cavernosa. cGMP degradation typically leads to smooth muscle contraction and detumescence prevented by PDE5i administration. Two other PDE5i, vardenafil and tadalafil are other PDE5i with different pharmacokinetics, PDE receptor selectivity and side effect profiles.
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older.  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). 
Cardiovascular diseases: The most common cause of cardiovascular diseases in the United States is atherosclerosis, the narrowing and hardening of arteries that reduces blood flow. Atherosclerosis (a type of vascular disease) typically affects arteries throughout the body; hypertension, high blood cholesterol levels, cigarette smoking, and diabetes mellitus aggravate atherosclerosis. Hardening of the arteries to the penis and pelvic organs, atherosclerosis, causes insufficient blood flow into the penis. There is a close correlation between the severity of atherosclerosis in the coronary arteries and erectile dysfunction. For example, men with more severe coronary artery atherosclerosis (hardening of the arteries in the heart) also tend to have more erectile dysfunction than men with mild or no coronary artery atherosclerosis. Some doctors suggest that men with new onset erectile dysfunction undergo evaluation for silent coronary artery diseases (advanced coronary artery atherosclerosis that has not yet caused angina or heart attacks).
Another potential new treatment consists of penile low-intensity shock wave lithotripsy. This consists of 1500 shocks twice a week for 3–6 weeks. The purpose is to stimulate neovascularisation to the corporal bodies with improvement in penile blood flow and endothelial function. The use of low-intensity shock wave lithotripsy may convert PDE5 inhibitor non-responders to responders.47
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.
VED involved placing the penis in a clear plastic tube where negative pressure created by the vacuum pump leads to penile engorgement and tumescence. Usually a constriction ring can be placed on the base of penis following penile engorgement. Some men complain of bruising, a “cold” penis and pain associated with the constriction ring; however, in some men with NED sensation may not be intact mitigating the side effects of VEDs. VEDs have reported effectiveness up to 90% in certain ED populations and it remains a non-invasive means to achieve and erection.
High cholesterol and triglyceride levels increase the risk of cardiovascular disease. Getting your cholesterol and triglyceride levels in an optimal range will help protect your heart and blood vessels. Cholesterol management may include lifestyle interventions (diet and exercise) as well as medications to get your total cholesterol, LDL, HDL, and triglycerides in an optimal range.
Some men report being helped by an oral medication called yohimbine, which comes from the bark of a tree that grows in India and Africa. This drug, which needs to be taken every day, has been reported to help about 20 to 25 percent of the men taking it. A relatively new but widely used oral medication called Viagra requires a careful medical evaluation by your doctor.
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.
With drug therapy, there’s a risk of side effects such as headaches, back pain or an upset stomach. Before taking any medication for erectile dysfunction it is important to ensure your doctor is ok with that decision. Medication may not work for all men, for instance, if you have diabetes or have previously had prostate surgery. ED medication might also have serious risks if you’re currently taking nitrates (commonly prescribed for chest pain), have heart disease or have low blood pressure.22
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).
In addition, when research has shown a nutrient such as zinc or niacin to improve sexual function, it's usually in people who are deficient in it. So, before you stock up on over-the-counter nutritional supplements for ED, speak with your doctor. He can test you for deficiencies and steer you toward the most effective and safest way to treat your erectile dysfunction.
Taking one of these tablets will not automatically produce an erection. Sexual stimulation is needed first to cause the release of nitric oxide from your penile nerves. These medications amplify that signal, allowing some men to function normally. Oral erectile dysfunction medications are not aphrodisiacs, will not cause excitement and are not needed in men who get normal erections.
Also called vacuum devices, penile pumps are devices that are placed over the penis to draw blood into the shaft. Once the vacuum creates an erection, the retaining band is slid down to the lower end of the penis and the pump is removed. An erection typically will last long enough for intercourse but your penis may be cold to the touch and the rubber band may restrict ejaculation.22
The common PDE5 inhibitor drugs approved in the United States are sildenafil (Viagra), vardenafil (Levitra and Staxyn, the generic form), tadalafil (Cialis), or avanafil (Stendra). All of the currently approved PDE5 inhibitors work in the same way. They differ in the number of available doses, how quickly they work and last in your system, the dosing, and to some extent in the side effects. However, they generally share the same indications and contraindications. Currently, tadalafil is the only medication that patients can take on a daily basis and is approved for the treatment of both ED and BPH (benign enlargement of the prostate).
It is important to understand that ED is frequently, if not usually, directly related to endothelial dysfunction, and that the release of NO by the vasculature of the penile arteries is directly related to the function of intact, healthy endothelium. In the face of endothelial dysfunction, the process of erection fails to occur in a normal fashion.16
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.
As with most other organ system in the human body, changes and loss of function is normal consequence of the ageing process. This is also true of the endocrine system, specifically the levels of testosterone production from the Leydig cells of the testicle. Accompanying the decrease in testosterone is a decrease in erections which also has a component in decrease in the blood supply to the penis making erection not as frequent and not as rigid compared with a young man’s erectile function. Although these changes are in itself not life threatening, they can impact a man’s relationship with his partner, and also ED may be a harbinger of other undiagnosed conditions such as coronary artery disease (CAD), hypercholesterolaemia or diabetes mellitus.6
In this study, ED proceeded CVD in almost 70% of cases. Similarly, many men with ED have been found to have pre-existing CVD. A study by Vlachopoulos et al evaluated the incidence of asymptomatic CVD in 50 men with ED.22 These authors found that 19% of men with ED had asymptomatic CVD. Similarly, Mulhall and colleagues found that 20% of men presenting with ED and vascular insufficiency on penile duplex had asymptomatic CVD.23
3. Are there physical causes of erectile dysfunction? Erectile dysfunction may be a symptom of underlying medical conditions, which if not detected may cause further medical problems. A prior history of cigarette smoking, heart attacks, strokes, and poor circulation in the extremities (for example, intermittent claudication or cramping in your leg[s] when you walk) suggest atherosclerosis as the cause of the erectile dysfunction. Loss of sexual desire and drive, lack of sexual fantasies, gynecomastia (enlargement of breasts), and diminished facial hair suggest low testosterone levels. A prior history of pelvic surgery or radiation and trauma to the penis/pelvis/perineum can cause problems with the nerves and blood vessels. Symptoms of intermittent claudication of the lower extremities with exercise may suggest a vascular problem as a cause of the erectile dysfunction.
Cosgrove et al reported a higher rate of sexual dysfunction in veterans with posttraumatic stress disorder (PTSD) than in veterans who did not develop this problem.  The domains on the International Index of Erectile Function (IIEF) questionnaire that demonstrated the most change included overall sexual satisfaction and erectile function. [43, 44] Men with PTSD should be evaluated and treated if they have sexual dysfunction.
A physical cause can be identified in about 80% of cases. These include cardiovascular disease, diabetes mellitus, neurological problems such as following prostatectomy, hypogonadism, and drug side effects. Psychological impotence is where erection or penetration fails due to thoughts or feelings; this is somewhat less frequent, in the order of about 10% of cases. In psychological impotence, there is a strong response to placebo treatment.
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).
The dose of PDE5 inhibitor that you start with may vary with underlying medical conditions and medications that you are taking. Thus, it is important to review all medications (even over the counter medications) with your physician. Typically, one starts with a lower dose and increases as needed. Some medical conditions prevent going up to higher doses. You can review the drug prescribing information or consult with your doctor regarding the dose(s) that are appropriate for you.
Erectile problems can happen to men of any age. There are many factors that contribute to ED including poor health, untreated medical problems, medications and pornography use. Many men struggle with understanding when they are experiencing situational sexual dysfunction verses when is your erectile issue an ongoing problem that requires medical help.
Alprostadil is a potent vasodilator and smooth muscle relaxant identical to the naturally occurring PGE1. PGE1 binds with specific receptors on smooth muscle cells and activates intracellular adenylate cyclase to produce cAMP, which in turn induces tissue relaxation through a second messenger system (96). PGE1 is the only FDA approved form of intracavernosal therapy and is available commercailly as EDEX, or Caverject. Its efficacy was demonstrated in several clinical trials where the rate of responders ranged from 40% to 80% (97,98). The most common adverse event is penile pain, which is not related to the injection of the medication itself. In men with prolonged use the pain is usually self-limited (99).
If you’re experiencing psychological ED, you may benefit from talk therapy. Therapy can help you manage your mental health. You’ll likely work with your therapist over several sessions, and your therapist will address things like major stress or anxiety factors, feelings around sex, or subconscious conflicts that could be affecting your sexual well-being.