When sexually stimulated there is a release of a chemical, nitric oxide (NO) in the blood vessels of the corpus cavernosum. The NO stimulates the production of a compound called cGMP, which causes relaxation of the smooth muscle in the blood vessels supplying the corpus cavernosum. PDE 5 is an enzyme that breaks down cGMP. By inhibiting the breakdown of cGMP by PDE5, these medications allow cGMP to build up in the penis. cGMP causes muscles in the corpora cavernosa of the penis to relax. When the muscle is relaxed, more blood can flow into the penis and fill the spaces in the penis. As the penis fills with blood, the veins in the penis are compressed, and this results a hard erection. When the effect on PDE5 decreases, the cGMP levels go down and the muscle in the penis contracts, causing less blood to flow into the penis and allowing the veins to open up and drain blood out of the penis.
There are, as you listen to all of the advertisements, if your erection lasts for more than four hours, there are very, very unusual cases where that can happen. There are very rare cases of visual problems. There are even rarer cases of hearing problems. But with every medication, there always a potential downside. But the absolute contraindication is an unstable medical condition, an unstable cardiovascular condition, being on nitrates.
Peyronie's disease is a condition associated with ED. Peyronie's disease is thought to result from minor repetitive trauma to the penis that leads to scarring of the tunica albuginea. It is often associated with a palpable scar in the penis, plaque. The scarring can cause the penis to curve in the direction of the scar, along with painful erections and erectile dysfunction. Some treatments for Peyronie's disease (excision of the plaque and placement of new tissue in its place, grafting) may cause ED also.
Alcohol abuse is the leading cause of impotence and other disturbances in sexual dysfunction.[3] Episodic erectile failure in alcoholic men is fairly routine, found to be significantly higher in men consuming more than three standard units of alcohol (12 g ethanol) daily and in subjects smoking more than 10 cigarettes/day.[4] Van Thiel and Lester[5] reported that 61% of patients dependent on alcohol reported sexual dysfunction, the most common being erectile dysfunction followed by reduced sexual desire. Erectile dysfunction and reduced sexual desire were frequently seen to be coexisting.[6–9] Vijayasenan,[10] found that of 97 male inpatients admitted for the treatment of alcoholism, 71% suffered from sexual dysfunction for a period of more than 12 months prior to admission to a hospital. The disturbances noted were diminished sexual desire (58%), ejaculatory incompetence (22%), erectile impotence (16%) and premature ejaculation (4%). Virtually all aspects of the human sexual response are affected by alcohol especially sexual desire and erection.[11]
I think that a very powerful argument to young men who want to perform at the highest level is to point out the destructive nature of what they’re doing. If they’re having 18 drinks per week, if they’re having three, four, five drinks at any one time, they’re going to guarantee that their erections are not going to be at the highest level. I can’t tell you the number of men who come in saying, they went out, they had a date, they had a big dinner– which, by the way, is also not a great thing for erections, because all the blood is now going to your gut instead of to the genital area. And how important lifestyle changes are to improving your performance, as well, if not better, than the medications. So make certain that you exercise modestly, not excessively. Make certain that you have a smaller meal on an evening or a day that you want to have a sexual encounter, because you want the blood to go, once again, to the penile area and not to your gut. And really, the whole idea of stress– if you’re stressed out, if you’re worried about a lot of things, if you’re distracted, you can’t initiate that psychic stimulus to your spinal cord and then ultimately to your penis. So stress management is incredibly important.
Obesity. Obesity itself is not a risk factor for ED — but there is a connection. “The bigger concern is that obesity can lead to type 2 diabetes or vascular diseases, which are risk factors for ED,” says Montague. Morbid obesity, a term used to classify individuals who are significantly overweight, can cause hormonal changes that are triggered by excess body fat. In addition, obesity can put physical limitations on sexual intercourse.
In regard to circulation, alcohol causes the blood vessels to dilate, which influences the way the blood moves in and out of the penis. A good blood flow regulates the relaxation and contraction of the penis, so it can get and maintain an erection. Without it, no matter how much you may want it to happen differently, your penis will simply remain flaccid.
Instead of injecting a medicine, some men insert a suppository of alprostadil into the urethra. A suppository is a solid piece of medicine that you insert into your body where it dissolves. A health care professional will prescribe a prefilled applicator for you to insert the pellet about an inch into your urethra. An erection will begin within 8 to 10 minutes and may last 30 to 60 minutes.
Patients taking PDE5 inhibitors should avoid consuming large amounts of alcohol, which may cause a sudden decrease in blood pressure when getting up from a standing or reclining position. Although effects can be variable, symptoms may include a fast heart rate, dizziness, headache and fainting. Studies with some PDE5 inhibitors have shown a decrease in blood pressure and symptomatic effects when combined with alcohol.

Risks associated with injection therapy including bleeding, pain with injection, penile pain, priapism, and corporal fibrosis (scarring inside of the corpora cavernosa). There is also concern that repetitive injections in the same area could cause scar tissue to build up in the tunica albuginea that could create penile curvature. Thus, doctors recommended that one alternate sides with injection and perform injections no more frequent than every other day.

Anxiety is the most common cause of erectile dysfunction in young men. This can include nervousness about getting your partner pregnant, losing your erection while putting a condom on, or your sexual performance. This often creates a negative spiral, because failure to achieve an erection causes yet more anxiety and stress. Depression, anxiety and stress can also cause ED by reducing libido.


In the evaluation of physical causes of ED, the health care provider is assessing for conditions that may affect the nerves, arteries, veins, and functional anatomy of the penis (for example, the tunica albuginea, the tissue surround the corpora). In determining a physical (or organic) cause, your health care provider will first rule out certain medical conditions, such as high blood pressure, high cholesterol, heart and vascular disease, low male hormone level, prostate cancer, and diabetes, which are associated with erectile dysfunction. Medical/surgical treatment of these conditions may also cause ED. In addition to these health conditions, certain systemic digestive (gastrointestinal) and respiratory diseases are known to result in erectile dysfunction:
Tadalafil shares the common side effects of the PDE5 inhibitors, however, due to its effect on PDE11, another phosphodiesterase located in muscle, tadalafil has been associated with muscle aches. Back pain and muscle aches occur in less than 7% of men taking tadalafil and in most patients will go away without treatment within 48 hours. When treatment was necessary, acetaminophen (Tylenol) and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil) or naproxen (Aleve) were effective. Rarely do the muscle aches and back pain cause men to stop using tadalafil.
Our team includes a sex advisor/counselor who can help you understand what is making you anxious around sex, and give you techniques to decrease your anxiety about sex. He has also helped many of our younger patients get better at sex. We also have an exercise physiologist, who will work with you on both diet and exercise, which can have a profound effect on the quality of your erections.
Pornography addiction or dependence is a potential cause for ED that many men fail to consider. If you spend a great deal of time watching and masturbating to pornography, it could cause you to develop unrealistic expectations about sex or about your sexual partners. When this happens, your brain becomes “trained” to not only expect but, in a way, to need that kind of experience in order to achieve arousal and climax. Researchers have actually studied this effect and have given the condition its own name – pornography-induced erectile dysfunction (PIED).
Sildenafil should be taken 1–2 h before intercourse. It is important to tell patients that the drug’s effectiveness requires sexual stimulation. One patient in our clinic recently complained that he had no effect from taking sildenafil. It was later discovered that he took the pill and then sat on his couch and read a book about how to grow tomatoes!
The connection between diabetes and ED is related to your circulation and nervous system. Poorly controlled blood sugar levels can damage small blood vessels and nerves. Damage to the nerves that control sexual stimulation and response can impede a man’s ability to achieve an erection firm enough to have sexual intercourse. Reduced blood flow from damaged blood vessels can also contribute to ED.

The physical exam should focus on femoral and peripheral pulses, femoral bruits (vascular abnormalities), visual field defects (prolactinoma or pituitary mass), breast exam (hyperprolactinemia), penile strictures (Peyronie’s disease), testicle atrophy (testosterone deficiency), and asymmetry or masses (hypogonadism). A rectal exam allows for assessment of both the prostate and sphincter tone, abnormalities that are associated with autonomic dysfunction. Sacral and perineal neurological exam will help in assessing autonomic function.

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.
The penis is composed of three cylinders: two on the top, the corpora cavernosa and one on the bottom, the corpus spongiosum. All of these are involved in the process of an erection. The corpora cavernosa are composed of potential spaces that can distend with blood, causing rigidity of the penile shaft. The corpus spongiosum is important for rigidity of the glans of the penis. When aroused, stimulated chemicals are released from the nervous system (nitric oxide is one) that stimulate the arteries to the penis to relax and increase blood flow into the penis. These potential spaces, like a sponge, can expand when more blood flow comes in the penis. Each corpora cavernosa is surrounded by an outer coating the tunica albuginea. When the penis fills with blood, these potential spaces, the sinusoids, compress the veins in the corpora against the side of the tunica albuginea, thus preventing blood from leaving the penis. It is this compression of the veins that allows for the erection to become fully rigid.
Is your erectile dysfunction due to psychological (stress, relationship problems, etc.) or physical factors? Your doctor may ask if you note erections at night or in the early morning. Men have involuntary erections in the early morning and during REM sleep (a stage in the sleep cycle with rapid eye movements). Men with psychogenic erectile dysfunction (erectile dysfunction due to psychological factors such as stress and anxiety rather than physical factors) usually maintain these involuntary erections. Men with physical causes of erectile dysfunction (for example, atherosclerosis, smoking, and diabetes) usually do not have these involuntary erections. Men with psychogenic erectile dysfunction may relate the onset of problems to a "stressor," such as failed relationship. Your doctor may suggest a test to determine if you have erections during sleep, which may suggest that there may be a psychological cause of the erectile dysfunction.
Since the decrease in T levels is often a consequence of obesity or weight gain (51), the milestone of treating testosterone deficiency in obese men is encouraging substantial lifestyle changes, including physical activity and weight loss. In fact, it is universally recognized that a low calorie diet or bariatric surgery can induce a significant increase in T plasma levels, reaching 10 nmol/L with the most invasive surgical procedures (62). Weight loss-induced T rise is more evident in young individuals (62), and, therefore, it must be strongly recommended in this age band.
The study, led by the University of Exeter and the University of Oxford, looked at data on more than 220,000 men across three cohorts, 6,000 of whom experienced erectile dysfunction. The research echoed recent findings that erectile dysfunction has a genetic cause, and goes further by opening the possibility that living a healthier lifestyle may help reduce risk.
Like all diabetic complications, ED can occur even when you have followed your doctor’s advice and carefully managed your diabetes. Also like all diabetes complications, ED is less likely to occur with good blood sugar control. Poorly controlled diabetes and high cholesterol increase the chances of vascular complications, which may lead to ED or other circulatory problems. In addition, regular smoking and alcohol use can contribute to ED.
×