Erections are neurovascular events, meaning that nerves and blood vessels (arteries and veins) are involved in the process of an erection and all must work properly to develop a hard erection that lasts long enough. Erection begins with sexual stimulation. Sexual stimulation can be tactile (for example, by a partner touching the penis or by masturbation) or mental (for example, by having sexual fantasies, viewing porn). Sexual stimulation or sexual arousal causes the nerves going to the penis to release a chemical, nitric oxide. Nitric oxide increases the production of another chemical, cyclic GMP (cGMP), in the muscle of the corpora cavernosa. The cGMP causes the muscles of the corpora cavernosa to relax, and this allows more blood to flow into the penis. The incoming blood fills the corpora cavernosa, making the penis expand.

While studies are limited, it has been shown that male sexual dysfunction can also negatively impact the sexual function of female partners. A study comparing the sexual function of women with partners with erectile dysfunction to those without showed that sexual arousal, lubrication, orgasm, satisfaction, pain and total score were significantly lower in those who had partners with erectile dysfunction. Later in that study, a large proportion of the men with erectile dysfunction underwent treatment. Following treatment, sexual arousal, lubrication, orgasm, satisfaction and pain were all significantly increased. It was concluded that female sexual function is impacted by male erection status, which may improve following treatment of male sexual dysfunction.

Low-intensity extracorporeal shock wave therapy has been proposed as a new non-invasive treatment for erectile dysfunction caused by problems with blood vessels. Shock wave therapy machines are now available in some medical practices in Australia. Although there is some evidence that it may help a proportion of men with erectile dysfunction, more research is needed before clear recommendations on its use can be made.
Total testosterone levels: Health care professionals should obtain a patient's blood samples for total testosterone levels in the early morning (before 8 a.m.) because the testosterone levels go up and down throughout the day. If you have a low testosterone level, a health care professional should check it again to confirm that it is truly low. In some men, a specialized test measuring the active form of testosterone (free or bioavailable testosterone) may be recommended.

Implantable penile prostheses are usually considered a last resort for treating impotence. They are implanted in the corpora cavernosa to make the penis rigid without the need for blood flow. The semirigid type of prosthesis consists of a pair of flexible silicone rods that can be bent up or down. This type of device has a low failure rate but, unfortunately, it causes the penis to always be erect, which can be difficult to conceal under clothing.
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.
The development of an erection is a complex event involving integration of psychologic, neurologic, endocrine, vascular, and local anatomic systems. Positron emission tomography scanning studies have suggested that sexual arousal is activated in higher cortical centers that then stimulate the medial preoptic and paraventricular nuclei of the hypothalamus.5 These signals ultimately descend through a complex neural network involving the parasympathetic nervous system and eventually activate parasympathetic nerves in the sacral area (S2 to S4).
Erectile dysfunction (ED) is one of the most common conditions affecting middle-aged and older men. Nearly every primary care physician, internist and geriatrician will be called upon to manage this condition or to make referrals to urologists, endocrinologists and cardiologists who will assist in the treatment of ED. This article will briefly discuss the diagnosis and management of ED. In addition, emerging concepts in ED management will be discussed, such as the use of testosterone to treat ED, the role of the endothelium in men with ED and treating the partner of the man with ED. Finally, future potential therapies for ED will be discussed.
Tadalafil should not be used with alpha-blockers (except Flomax), medicines used to treat high blood pressure, and benign prostate hypertrophy (BPH) because the combination of tadalafil and an alpha-blocker may lower the blood pressure greatly and lead to dizziness and fainting. Examples of alpha-blockers include tamsulosin (Flomax), terazosin (Hytrin), doxazosin (Cardura), alfuzosin (Uroxatral), and prazosin (Minipress). Tamsulosin (Flomax) is the only alpha-blocker that patients can use safely with tadalafil. When tadalafil (20 mg) was given to healthy men taking 0.4 mg of Flomax daily, there was no significant decrease in blood pressure and so patients on this dose of tamsulosin (Flomax) can be prescribed tadalafil. The only alpha-blocker not tested with tadalafil is alfuzosin (Uroxatral), and no recommendations can be made regarding the interaction between the two.
The liver is the largest gland and organ in the body. There are a variety of liver diseases caused by liver inflammation, scarring of the liver, infection of the liver, gallstones, cancer, toxins, genetic diseases, and blood flow problems. Symptoms of liver disease generally do not occur until the liver disease is advanced. Some symptoms of liver disease include jaundice, nausea and vomiting, easy bruising, bleeding excessively, fatigue, weakness, weight loss, shortness of breath, leg swelling, impotence, and confusion. Treatment of diseases of the liver depends on the cause.
The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of hims, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.
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.

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.


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.
There are risks to prosthetic surgery and patients are counselled before the procedure. If there is a post-operative infection, the implant will likely be removed. The devices are reliable, but in the case of mechanical malfunction, the device or a part of the device will need to be replaced surgically. If a penile prosthesis is removed, other non-surgical treatments may no longer work.
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