Diabetes is a well-recognized risk factor for ED. A systematic review and meta-analysis found that the prevalence of ED was 37.5% in type 1 diabetes, 66.3% in type 2 diabetes, and 52.5% in diabetes overall—a rate approximately 3.5 times higher than that in controls.  The etiology of ED in diabetic men probably involves both vascular and neurogenic mechanisms. Evidence indicates that establishing good glycemic control can minimize this risk.
Jump up ^ Reepmeyer JC, Woodruff JT (2007). "Use of liquid chromatography-mass spectrometry and a chemical cleavage reaction for the structure elucidation of a new sildenafil analogue detected as an adulterant in an herbal dietary supplement". Journal of Pharmaceutical and Biomedical Analysis. 44 (4): 887–93. doi:10.1016/j.jpba.2007.04.011. PMID 17532168.
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.
What you need to know about delayed ejaculation Delayed ejaculation is a sexual disorder that can be distressing for a man and his partner and may disrupt a relationship. There are many reasons why delayed ejaculation occurs, including tissue damage, age, drugs, and the side effects of medication. They may be physiological or psychological. Find out how to get help. Read now
Lifestyle choices that impair blood circulation can contribute to ED. Smoking, excessive drinking, and drug abuse may damage the blood vessels and reduce blood flow to the penis. Smoking makes men with atherosclerosis particularly vulnerable to ED. Being overweight and getting too little exercise also contribute to ED. Studies indicate that men who exercise regularly have a lower risk of ED.
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.”
Psychotherapy, marital counseling, or sex therapy may be helpful in treating cases of impotence that have psychological or emotional causes. A range of other treatments exists for cases of impotence that arise from purely physiological causes. These treatments include vacuum devices, penile injections, and penile implants. These mechanical or physically invasive approaches have largely been superseded, however, by the drug sildenafil citrate (trade name Viagra), which is taken in pill form. This drug works by enhancing the effects of nitric oxide, a chemical that, upon sexual stimulation, is normally released to widen the blood vessels supplying the penis. The increased flow of blood through those vessels into certain tissues in the penis causes an erection. See also sexual dysfunction.
To reach the largest audience, communications strategies should include informative and accurate newspaper and magazine articles, radio and television programs, as well as special educational programs in senior centers. Resources for accurate information regarding diagnosis and treatment options also should include doctors' offices, unions, fraternal and service groups, voluntary health organizations, State and local health departments, and appropriate advocacy groups. Additionally, since sex education courses in schools uniformly address erectile function, the concept of erectile dysfunction can easily be communicated in these forums as well.
It is necessary to identify the causes of worry and try to remove these. They could include concern about personal relationships, work, family problems, health or even sexual “performance” with a new or old partner. It is often said that the brain is the biggest sex organ of them all – if it is too busy with other things, it will not be involved in arousal and the erection that follows.
Stiffy Solution: The good news is, almost all of these conditions can be successfully treated if you catch them early on. And since erectile problems may be the first side effect your dude has experienced, seeking medical treatment for his erectile problems may be the thing to get him into a doctor's office. So if your dude is a well-rested, non-drinking, non-smoking, paragon of relaxation who suddenly can't get wood, urge him to talk to his doctor — his misbehaving penis may actually be communicating something way more important than "Not tonight, honey."
Associated morbidity may include various other male sexual dysfunctions, such as premature (early) ejaculation and male hypoactive sexual desire disorder. The NHSLS found that 28.5% of men aged 18-59 years reported premature ejaculation, and 15.8% lacked sexual interest during the past year. An additional 17% reported anxiety about sexual performance, and 8.1% had a lack of pleasure in sex. 
NO is produced by the enzyme NO synthase (NOS).  NOS plays many roles, ranging from homeostasis to immune system regulation. To date, 3 subtypes have been identified: nNOS, iNOS, and eNOS, which are produced by the genes NOS1, NOS2, and NOS3, respectively. This nomenclature is derived from the sources of the original isolates: neuronal tissue (nNOS), immunoactivated macrophage cell lines (iNOS), and vascular endothelium (eNOS). The subtypes are not, however, limited to the tissues from which they were first isolated.
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. 
Erectile dysfunction (ED) affects 50% of men older than 40 years,  exerting substantial effects on quality of life.  This common problem is complex and involves multiple pathways. Penile erections are produced by an integration of physiologic processes involving the central nervous, peripheral nervous, hormonal, and vascular systems. Any abnormality in these systems, whether from medication or disease, has a significant impact on the ability to develop and sustain an erection, ejaculate, and experience orgasm.
Erection dissatisfaction can actually enhance lovemaking. The dark cloud of erection changes has a silver lining. Young couples often have problems because young men become aroused faster than young women. Young men are often all finished before young women have even started to get aroused. Post-50 erection changes slow men’s arousal process so their erotic pace more closely matches women’s. A slower pace allows plenty time for kissing, cuddling, and whole-body massage, all essential to most women’s enjoyment of sex. Seen in this light, for many older couples, erection dissatisfaction can be a gift.
What’s important to take away from this is that, because erections can occur throughout the day for no reason, erectile dysfunction can be difficult to diagnose. Some men achieve erections for no reason, yet when provided with stimuli, they aren’t able to. Some men, on the other hand, only get aroused when directly stimulated. This means that healthcare professionals need to take into account many variables prior to diagnosing and treating erectile dysfunction.
But he may have a real problem. Generally, erectile dysfunction is linked to cardiovascular health. If your guy has serious health problems, drinks and smokes too much, or does too many drugs, those conditions may play a role. Obesity, heart disease, prescription medications, and diabetes are just a few of the common risk factors. And then there are the psychological causes: depression, stress, and the million things flashing through his head when he's struggling to get it on.
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.
This may be the oldest excuse in the book as a reason not to have safe sex, but research has confirmed that condoms may interfere with some men’s ability to have and hold an erection. For example, a 2006 study found that, over a three-month period, about 37 percent of men lost at least one erection when putting on a condom, or during sex with a condom, SexualHealth.com reported.
One report from a recent community survey concluded that erectile failure was the leading complaint of males attending sex therapy clinics. Other studies have shown that erectile disorders are the primary concern of sex therapy patients in treatment. This is consistent with the view that erectile dysfunction may be associated with depression, loss of self-esteem, poor self-image, increased anxiety or tension with one's sexual partner, and/or fear and anxiety associated with contracting sexually transmitted diseases, including AIDS.
Over the past century, Western culture has become more focused on working, working out, working on this and that, and eating right that so many Americans are stressed and … quite simply … overworked. Stress is a leading cause of erectile dysfunction as it takes away focus. When a man is intent on being intimate with his wife, thoughts of deadlines, paychecks, and bills may creep into his mind. This can lead to difficulties achieving or maintaining an erection, and unfortunately, this only leads to more stress, anxiety, and depression within a marriage.
None of the ED drugs is safe to take with cardiac drugs called nitrates because it could cause a dangerous drop in blood pressure. Drugs that many men take for urinary symptoms, called alpha blockers, can also lower blood pressure, so take them at least four hours apart from ED drugs. Your doctor may start you on a smaller dose of the ED drug if you already take an alpha blocker, or may recommend the alpha blocker tamsulosin (Flomax), which affects blood pressure less.
Medications: Many common medicines produce erectile dysfunction as a side effect. Medicines that can cause erectile dysfunction include many used to treat high blood pressure, antihistamines, antidepressants, tranquilizers, and appetite suppressants. Examples of common medicines that can cause erectile dysfunction include propranolol (Inderal) or other beta-blockers, hydrochlorothiazide, digoxin (Lanoxin), amitriptyline (Elavil), famotidine (Pepcid), cimetidine (Tagamet), metoclopramide (Reglan), naproxen, indomethacin (Indocin), lithium (Eskalith, Lithobid), verapamil (Calan, Verelan, Isoptin), phenytoin (Dilantin), gemfibrozil (Lopid), amphetamine/dextroamphetamine (Adderall), and phentermine. Prostate cancer medications that lower testosterone levels such as leuprolide (Lupron) may affect erectile function. Some chemotherapies such as cyclophosphamide (Cytoxan) may affect erectile function.
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.
Sexual dysfunction and ED become more common as men age. The percentage of complete ED increases from 5% to 15% as age increases from 40 to 70 years. But this does not mean growing older is the end of your sex life. ED can be treated at any age. Also, ED may be more common in Hispanic men and in those with a history of diabetes, obesity, smoking, and hypertension. Research shows that African-American men sought medical care for ED twice the rate of other racial groups.