Normal penile erection is controlled by two mechanisms: reflex erection and psychogenic erection. Reflex erection occurs by directly touching the shaft of the penis, while psychogenic erection occurs by erotic or emotional stimuli. ED is a condition where erection does not take place by either mechanism. ED can occur because of hormonal imbalance, neural disorders or lack of adequate blood supply to the penis.54 Lack of blood supply can be a result of impaired endothelial function associated with CAD.54
Now that we better appreciate the complex sequence of events necessary for erections to occur, it’s no surprise that testosterone alone yields less than perfect results. Erectile dysfunction represents more than just low testosterone, which is just one facet of the spectrum of dysfunctional phenomena that cause sexual dysfunction. Nonetheless, when testosterone is combined with popular drugs like Viagra®, success is enhanced to an even greater degree—orgasmic function improves, along with erectile capacity and libido.20 Testosterone also activates penile nitric oxide; ultrasound studies have demonstrated a 27% increase in arterial blood flow into the penis with testosterone supplementation.23
Age is a critical risk factor for the development of ED and endothelial dysfunction.4,5 ED is the most common condition occurring in middle-aged and older men.5 Kinsey et al. reported that 25 % of 65-year-old men and 75 % of ≥80-year-old men have ED.39 Moreover, ageing also decreases endothelial function, which is responsible for IHD.5 The incidence and severity of ED increases with age (a man aged 70 years is three-times more likely to have ED than a man aged 40 years).40
Abstract | Full Text | Full Text PDF | PubMed | Scopus (164) | Google ScholarSee all References Several double-blind, placebo-controlled studies have shown vardenafil to be more effective than placebo in the treatment of ED secondary to a wide range of other etiologies as well.71x71Hellstrom, WJ, Gittelman, M, Karlin, G..., and Vardenafil Study Group. Sustained efficacy and tolerability of vardenafil, a highly potent selective phosphodiesterase type 5 inhibitor, in men with erectile dysfunction: results of a randomized, double-blind, 26-week placebo-controlled pivotal trial. Urology. 2003; 61: 8–14
Considering the fact that CV disease presents with higher incidence in patients with erectile dysfunction while at the same time sexual activity by itself poses potential CV risks, the appropriate management of those complex conditions is of utmost importance. Accordingly, the working group of the third Princeton Consensus Conference developed practical guidelines and a simplified algorithm in order to manage sexual dysfunction and sexual activity implementation issues in patients with different levels of CV risk, including hypertensive patients[90].

Abstract | PubMed | Scopus (136) | Google ScholarSee all References Other candidate mechanisms linking ED and cigarette smoking include hypercoagulability and increased platelet aggregation, increased release of free fatty acids and catecholamines, changes in NO synthetic pathways, and a possible direct toxic effect on vascular endothelium.13x13Chung, WS, Shim, BS, and Park, YY. Hemodynamic insult by vascular risk factors and pharmacologic erection in men with erectile dysfunction: Doppler sonography study. World J Urol. 2000; 18: 427–430
Faced with concern about ED pills and the heart, the FDA has urged caution in patients who have suffered heart attacks, strokes, or serious disturbances of the heart's pumping rhythm in the previous six months, in men with a history of congestive heart failure or unstable angina, and in men with low blood pressure or uncontrolled high blood pressure (above 170/110 mm Hg). Because certain medications can boost the blood levels of these drugs, men taking erythromycin or certain antifungal or anti-HIV medications should use only low-dose PDE-5 inhibitors. Reduced dosage is also important for men with advanced age and for those with significant kidney or liver disease.

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
Now that we better appreciate the complex sequence of events necessary for erections to occur, it’s no surprise that testosterone alone yields less than perfect results. Erectile dysfunction represents more than just low testosterone, which is just one facet of the spectrum of dysfunctional phenomena that cause sexual dysfunction. Nonetheless, when testosterone is combined with popular drugs like Viagra®, success is enhanced to an even greater degree—orgasmic function improves, along with erectile capacity and libido.20 Testosterone also activates penile nitric oxide; ultrasound studies have demonstrated a 27% increase in arterial blood flow into the penis with testosterone supplementation.23
The use of penile support device such as penile cast worn externally during intercourse has been tried to provide length and rigidity to the penile shaft (24). Each device can be customised to the patient’s penile size and provided an option for patients who are seeking non-pharmaceutical/non-invasive treatment, or have end-organ failure who may not be candidates for, or unable to afford, penile prosthesis implant.

These medications don’t work for everyone but they are easy to use and work for around 60% of people who try them. They work by making it easier to get an erection by reducing the effect of (inhibiting) the chemical PDE-5. This chemical is used in the body to make sure there isn’t too much blood in the penis during an erection, but if you have erectile dysfunction then this chemical ends up over-compensating.
Nebivolol seems to have an advantage over other beta-blockers when used to treat men with hypertension and ED. It has additional vasodilating effects because it stimulates endothelial release of nitric oxide (NO), resulting in relaxation of smooth muscle in the corpus cavernosum, allowing penile erection.25 Despite limited studies, nebivolol does not seem to worsen erectile function and some studies have demonstrated significant improvement in erectile function with nebivolol compared with second-generation cardioselective beta-blockers.23,26–28
Abstract | Full Text | Full Text PDF | PubMed | Scopus (164) | Google ScholarSee all References Several double-blind, placebo-controlled studies have shown vardenafil to be more effective than placebo in the treatment of ED secondary to a wide range of other etiologies as well.71x71Hellstrom, WJ, Gittelman, M, Karlin, G..., and Vardenafil Study Group. Sustained efficacy and tolerability of vardenafil, a highly potent selective phosphodiesterase type 5 inhibitor, in men with erectile dysfunction: results of a randomized, double-blind, 26-week placebo-controlled pivotal trial. Urology. 2003; 61: 8–14
Contraindications for TTh include (for detailed listing, please refer to Buvat et al.45) patients with breast or prostate cancer, while patients with a palpable prostate nodule or induration, or prostate-specific antigen >4 ng/mL (or >3 ng/mL in men at high risk for prostate cancer, such as African-Americans or men with first-degree relatives with prostate cancer), should first undergo urological evaluation. Testosterone therapy is contraindicated also in patients with haematocrit >50% (TTh increases haematocrit) and uncontrolled congestive heart failure (risk of fluid retention). Risk for adverse CVD events may be increased in patients and with the mode of treatment epitomized in the study of Basaria et al.46 (see earlier).

Despite the existing controversies, available data so far imply the old generation b-blockers (e.g., propranolol) as the major culprits for sexual dysfunction with the newer ones (carvedilol, celiprolol) to exert a less pronounced negative effect[21-24]. A luminous exception to the rule, nebivolol, is a newer agent of its class which significantly ameliorates erectile dysfunction through increased nitric oxide generation, an effect consistently demonstrated in recent studies[25,26]. Diuretics, even on adjunct therapy, constitute another antihypertensive agent negatively associated with sexual function[27-29]. On the other hand, calcium antagonists and angiotensin converting enzyme inhibitors seem to demonstrate a neutral effect[30-32]. Interestingly, angiotensin receptor blockers (ARBs) by blocking the vasoconstrictive action of angiotensin II seem to positively affect erectile function and are thus regarded as a first-line treatment in hypertensive patients with erectile dysfunction[22,25,33-35].
The obvious risks are the same that accompany any surgery: infection, pain, bleeding, and scarring. If for some reason the prosthesis or parts become damaged or dislocated, surgical removal may be necessary. With a general success rate of about 90 percent, any of the devices will restore erections, but they will not affect sexual desire, ejaculation, or orgasm.
The cardiovascular effects of sildenafil during exercise in patients with known or probable cardiovascular disease were studied in a randomized placebo-controlled trial of 105 men with a mean age of 66 years.63x63Arruda-Olson, AM, Mahoney, DW, Nehra, A, Leckel, M, and Pellikka, PA. Cardiovascular effects of sildenafil during exercise in men with known or probable coronary artery disease: a randomized crossover trial. JAMA. 2002; 287: 719–725
Although ED is a common complication of diabetes, its effect on quality of life is not well understood. Recent work for the Exploratory Comprehensive Evaluation of Erectile Dysfunction (ExCEED) database demonstrates that in the general population of patients presenting to their urologist, ED negatively affects both general and disease-specific health-related quality of life (HRQOL).35 While this study provides insight into the detrimental affect of ED on quality of life, the cohort is somewhat selected, in that all of the patients were seen in sexual dysfunction clinics and therefore may have been more likely to be bothered by their condition and to report worse quality of life.
Stem cell therapy is an attractive treatment modality and an appealing option for tissue regenerative therapy for ED. Stem cells are pluripotent cells that can be produced from multiple regions within the body. They have the potential to divide and differentiate into numerous kinds of human cells, such as endothelial cells and smooth muscle.79 The efficacy and safety of gene and stem cell therapy in patients with ED and IHD need to be extensively investigated because both seem to have the potential to correct underlying abnormalities in ED. This would be a huge development in terms of management options for patients with ED and IHD.
Gutiérrez-González, Enrique; Castelló, Adela; Fernández-Navarro, Pablo; Castaño-Vinyals, Gemma; Llorca, Javier; Salas-Trejo, Dolores; Salcedo-Bellido, Inmaculada; Aragonés, Nuria; Fernández-Tardón, Guillermo; Alguacil, Juan; Gracia-Lavedan, Esther; García-Esquinas, Esther; Gómez-Acebo, Inés; Amiano, Pilar; Romaguera, Dora; Kogevinas, Manolis; Pollán, Marina; Pérez-Gómez, Beatriz. “Dietary Zinc and Risk of Prostate Cancer in Spain: MCC-Spain Study.” Nutrients. Jan 2019, 11(1).

Crossref | PubMed | Google ScholarSee all References Risk factors for cardiovascular disease include diabetes mellitus, obesity, physical inactivity, hyperlipidemia, tobacco use, and hypertension. Often, the relative risk of each of these factors in the development of ED is difficult to assess because many patients with ED and cardiovascular disease have more than 1 risk factor. Another important consideration is the effect of cardiac disease itself on erectile function. A history of a prior myocardial infarction was not found to be a significant independent risk factor for ED in a study comparing sexual function in 50 patients who had a prior myocardial infarction with a control group of 50 patients.14x14Dhabuwala, CB, Kumar, A, and Pierce, JM. Myocardial infarction and its influence on male sexual function. Arch Sex Behav. 1986; 15: 499–504
There are other treatment options for erectile dysfunction (ED). Alprostadil is a medication that improves blood flow to the penis and improves erections. It can be given either by injection (Caverject and other brands) at the base of the penis or by putting an alprostadil gel (brand name MUSE) directly into the urethra, using a thin tube and a little lubricant so it slides in easily. The medicine is absorbed from the lining of the urethra into the surrounding tissues. The shot is less appealing to most people, of course, but more effective.
Organic nitrates are drugs that widen arteries by increasing their supply of nitric oxide; that's how they open the partially blocked coronary arteries in patients with angina. But because nitrates and ED pills both act on nitric oxide, the drugs don't mix; healthy volunteers given Viagra followed an hour later by nitroglycerin see their blood pressures drop by 25–51 mm Hg, a potentially dangerous amount. All experts agree that men who are taking nitrates cannot use ED pills; this includes all preparations of nitroglycerin (short-acting, under-the-tongue tablets or sprays), long-acting nitrates (isosorbide dinitrate or Isordil, Sorbitrate, and others, and isosorbide mononitrate, Imdur, ISMO, and others), nitroglycerin patches and pastes, and amyl nitrite or amyl nitrate (so-called poppers, which some men use for sexual stimulation).

Although the results provide evidence that PDE5 inhibitors may benefit heart health, the retrospective study design makes it impossible to ascertain direct cause and effect, Andersson noted. It is possible that using erectile dysfunction drugs simply indicates a more active sex life, which could itself contribute to, or be a marker of, a heart-healthy lifestyle overall.
Dey J. “Evaluation and treatment of erectile dysfunction in men with diabetes mellitus.” Mayo Clinic Proceedings 77. 2002. 276-282. Shabsigh R. “Erectile Dysfunction in Men with Diabetes Mellitus.” Men’s Sexual Health Consult Collection. 2006 Nov. Moore C, Wang R. “Pathophysiology and treatment of diabetic erectile dysfunction.” Asian J Andrology. 2006 Nov. 8: 67-684. Penson D, Latini D, Lubeck D, Wallace K, Henning J, Lue T. “Do impotent men with diabetes have more severe erectile dysfunction and worse quality of life than general population of impotent patients?” Diabetes Care 26. 2003. 1093-1099. Sun P, Cameron A, Seftel A, Shabsigh R, Niederberger C, Guay A. “Erectile dysfunction – an observable marker of diabetes mellitus? A large national epidemiological study.” Journal of Urology 176. 2006. 1081-1085.

Abstract | Full Text | Full Text PDF | PubMed | Scopus (66) | Google ScholarSee all References Risk of arrythmias after sexual intercourse was evaluated in 82 patients with stable coronary artery disease who were monitored with ambulatory ECG after sexual intercourse.81x81Drory, Y, Fisman, EZ, Shapira, Y, and Pines, A. Ventricular arrhythmias during sexual activity in patients with coronary artery disease. Chest. 1996; 109: 922–924


Relative risk and 95% confidence interval for erectile dysfunction and clinical events. Relative risk and 95% confidence interval for erectile dysfunction and total cardiovascular events (A), cardiovascular mortality (B), myocardial infarction (C), cerebrovascular events (D), and all-cause mortality (E). Studies are listed alphabetically. Boxes represent the relative risk and lines represent the 95% confidence interval for individual studies. The diamonds and their width represent the pooled relative risks and the 95% confidence interval, respectively. CVD, cardiovascular disease; DM, diabetes mellitus; HF, heart failure; GEN, general population. Numbers in brackets are the number of references in the text—and references with S are from Supplementary material online. With permission from Vlachopoulos et al.5
The medicine causes blood vessels to expand, increasing blood flow in the body and to the penis, thus helping patients to get an erection. Invasive surgeries that involve rods and balloons are also available to patients suffering from ED. While these treatments often come with potential side effects, discomfort and a financial burden, some ED patients may see success with them.
Low testosterone represents another link between erectile dysfunction and heart disease. A man’s testosterone levels gradually diminish beginning at age 30. By the time he reaches his 70s, testosterone levels may have dropped to a tenth of youthful levels. Diminishing testosterone levels contribute to loss of muscle, increased body fat, and reduced libido. Fatigue is common, as is depression. Low testosterone levels can also result in reduced concentration, irritability, passivity, loss of interest in activities, and even hypochondria.
Penile vibratory stimulator is a battery operated device with oscillating discs that can provide excitation of afferent penile nerves at various regulated frequency and amplitudes. PVS has been utilised to activate the ejaculatory reflex for patients with spinal cord injury above T10 seeking to collect retrogradely ejaculated semen in fertility treatment (10). The Viberect is a vibratory stimulation handheld device approved by FDA for treatment of ED. It is clamp-shaped with two oscillating discs facing each other near the tips, and the glans penis is placed between the two oscillating discs to receive concurrent dorsal and ventral stimulation at adjustable frequencies and amplitudes.
The vascular endothelium has an important role in angiogenesis and vascular repair by producing regulatory substances, including NO, prostaglandin, endothelins, prostacyclin and angiotensin II. These regulatory factors regulate the blood flow to the penis by controlling smooth muscle contractility and subsequent vasoconstriction and vasodilatation. Generally, in erectile tissue, increased blood flow through the cavernosal artery increases shear stress and produces NO, which further relaxes the vascular smooth muscles and increases blood flow in the corpora cavernosa.54 These events cause penile erection. However, in ED, endothelial NO synthesis is reduced and there is increased endothelial cell death (Figure 2).55
Three longitudinal studies have estimated incidence rates of ED in men with diabetes. Unfortunately, none of these studies specifically examined men with type 2 disease. In a cohort of 278 diabetic men with type 1 or type 2 diabetes potent at study entry, the proportion of patients reporting ED at 5-year follow-up was 28%.7 A follow-up analysis of the Massachusetts Male Aging Study, a community-based cohort of men between 40 and 70 years of age, found that the incidence of ED in the diabetic men was 51/1,000 population-years.8 This figure was similar to the 68/1,000 person-years crude incidence rate of ED reported in a study of 1,010 men with diabetes.5 However, new studies need to be carried out in well-characterized populations of men with diabetes in order to better determine the incidence of ED and potential effects of interventions to reduce complications.
Cardiovascular disease remains our nation’s biggest killer, responsible for about one-third of deaths in the U.S.1 Erectile dysfunction (ED) is typically the first clinical manifestation of cardiovascular disease, making it a helpful early marker for men who are likely to die of heart attacks. There is a strong relationship between erectile dysfunction and high blood pressure, high cholesterol, angina, stroke, heart attack and a premature death.2, 3
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Phosphodiesterase type 5 is found predominantly in the smooth muscle of the corpora cavernosa but can be found in smaller quantities in platelets and other vascular smooth muscle.56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C

Figure. Progression of atherosclerosis. Endothelial dysfunction occurs early in atherosclerosis and prevents blood vessels from dilating properly. When the blood vessels that supply the penis are not able to dilate during sexual stimulation because of endothelial dysfunction, the penis cannot fill with blood, and the man develops erectile dysfunction. As atherosclerosis progresses, plaques build up in blood vessels and blood flow is slowed, further worsening erectile function. A heart attack occurs when an atherosclerotic plaque in a coronary artery ruptures, a blood clot forms over the plaque, and blood flow to the heart muscle is completely blocked. Atherosclerotic risk factors (black arrows) worsen cardiovascular health; modification of these risk factors (red arrows) improves cardiovascular health.
DHEA is a hormone made by the human body. It’s a building block for testosterone. According to a study published in Urology, this supplement may be able to help men whose ED is related to having low testosterone. However, there’s no definitive evidence of this benefit. It’s clear that DHEA can cause various side effects, including liver damage and acne. Long-term use of DHEA can also cause hormonal imbalances.
Evaluation of functional capacity is the mainstay for the management of patients with ED.30 However, it should be kept in mind that in men with heart failure sexual activity may affect the heart differently from physical activity of similar METS due to differences in psychological anticipation and sympathetic activation.30,49 Cardiac echocardiography may offer valuable information for left ventricular performance and valvular function. For risk categories of heart failure patients and their management, please refer to Table 3 and Figure 5.
Relative risk and 95% confidence interval for erectile dysfunction and clinical events. Relative risk and 95% confidence interval for erectile dysfunction and total cardiovascular events (A), cardiovascular mortality (B), myocardial infarction (C), cerebrovascular events (D), and all-cause mortality (E). Studies are listed alphabetically. Boxes represent the relative risk and lines represent the 95% confidence interval for individual studies. The diamonds and their width represent the pooled relative risks and the 95% confidence interval, respectively. CVD, cardiovascular disease; DM, diabetes mellitus; HF, heart failure; GEN, general population. Numbers in brackets are the number of references in the text—and references with S are from Supplementary material online. With permission from Vlachopoulos et al.5

Poor sleep patterns can be a contributing factor for erectile dysfunction, Mucher says. One review published in the journal Brain Research emphasized the intricate relationship between the level of sex hormones like testosterone, sexual function, and sleep, noting that testosterone levels increase with improved sleep, and lower levels are associated with sexual dysfunction. Hormone secretion is controlled by the body’s internal clock, and sleep patterns likely help the body determine when to release certain hormones. 

You may reduce your risk of ED by improving your heart health. Healthy lifestyle choices often encourage you to stop smoking, lose weight and increase physical activity. If ED persists, oral medications are a common first therapy for ED. If oral medications don’t work for you, the penile implant may be an option. The implant is concealed inside the body. It offers support for an erection whenever and wherever desired.


Besides mammalian organs, insects and arthropods are also consumed as aphrodisiacs in Eastern medicine. These include scorpions, spiders, beetles, flies and other bugs (32). Penile erections can be observed following administration of neurotoxins as it causes repetitive firing of the somatic, sympathetic and parasympathetic neurons, resulting in autonomic and neuromuscular over-excitation. Scorpions are often used as an ingredient found in herbal wines. However, there is a general lack of literature regarding the consumption of scorpion neurotoxins for potency.
No matter what the cause of erectile dysfunction, it is likely to cause feelings of stress and other emotional reactions. It’s also not uncommon for erection problems to cause tension in a relationship, particularly if one or both partners withdraws emotionally and the problem is not talked about. And it’s possible for a man’s renewed ability to have intercourse after a period of no sexual activity to stir up relationship issues.
×