Nerves originating in the spinal cord and peripheral ganglia innervate the penis. There are autonomic (parasympathetic and sympathetic), and somatic separate and integrated pathways. The autonomic pathways neurons originate in the spinal cord and peripheral ganglia from the sympathetic and parasympathetic systems, respectively. They merge to form the cavernous nerves that travel alongside the prostate, enter the corpora cavernosa and corpus spongiosum to affect the neurovascular events required for tumescence and detumescence. The somatic nerves send sensory information from the penile skin, glans, and urethra via the dorsal penile nerve and pudendal nerve to the spinal cord. The somatic nerves also initiate contraction of the ischio- and bulbocavernosus muscles.

The sensitivity of the skin of the penis to detect vibrations (biothesiometry) can be used as a simple office nerve function screening test. This involves the use of a small vibrating test probe placed on the right and left side of the penile shaft as well as on the head of the penis. The strength of the vibrations is increased until you can feel the probe vibrating clearly. Although this test does not directly measure the erectile nerves, it serves as a reasonable screening for possible sensory loss and is simple to perform. More formal nerve conduction studies are only performed in selected cases.
Treatment involves addressing the underlying causes, lifestyle modifications, and addressing psychosocial issues.[2] In many cases, a trial of pharmacological therapy with a PDE5 inhibitor, such as sildenafil, can be attempted. In some cases, treatment can involve inserting prostaglandin pellets into the urethra, injecting smooth muscle relaxants and vasodilators into the penis, a penile prosthesis, a penis pump, or vascular reconstructive surgery.[2][3]
Inside the cell, NOS catalyzes the oxidation of L-arginine to NO and L-citrulline. Endogenous blockers of this pathway have been identified. The gaseous NO that is produced acts as a neurotransmitter or paracrine messenger. Its biologic half-life is only 5 seconds. NO may act within the cell or diffuse and interact with nearby target cells. In the corpora cavernosa, NO activates guanylate cyclase, which in turn increases cyclic guanosine monophosphate (cGMP). Relaxation of vascular smooth muscles by cGMP leads to vasodilation and increased blood flow.
The medications are extremely effective, which is very good. And the medications are, for the most part, extremely well-tolerated. But there are, like with any medications, a potential downside. The one absolute downside to the use of any of these erection what we call PDE5 medications is if a patient is using a nitroglycerin medication. And nitroglycerins are used for heart disease and for angina, for the most part, although there are some recreational uses of nitrites. And that’s important because your blood vessels will dilate and your blood pressure will drop. And that is an absolute contraindication.
A physical examination is necessary. The doctor will pay particular attention to the genitals and nervous, vascular, and urinary systems. Your blood pressure will be checked because several studies have demonstrated a connection between high blood pressure and erectile dysfunction. The physical examination will confirm information you gave the doctor in your medical history and may help reveal unsuspected disorders such as diabetes, vascular disease, penile plaques (scar tissue or firm lumps under the skin of the penis), testicular problems, low male hormone production, injury, or disease to the nerves of the penis and various prostate disorders.
Years ago, the standard treatment for impotence was an implantable penile prosthesis or long-term psychotherapy. Although physical causes are now more readily diagnosed and treated, individual or marital counseling is still an effective treatment for impotence when emotional factors play a role. Fortunately, other approaches are now available to treat the physical causes of impotence.

Surgical intervention for a number of conditions may remove anatomical structures necessary to erection, damage nerves, or impair blood supply.[8] Erectile dysfunction is a common complication of treatments for prostate cancer, including prostatectomy and destruction of the prostate by external beam radiation, although the prostate gland itself is not necessary to achieve an erection. As far as inguinal hernia surgery is concerned, in most cases, and in the absence of postoperative complications, the operative repair can lead to a recovery of the sexual life of people with preoperative sexual dysfunction, while, in most cases, it does not affect people with a preoperative normal sexual life.[13]
Many common medications for treating hypertension, depression, and high blood lipids (high cholesterol) can contribute to erectile dysfunction (see above). Treatment of hypertension is an example. There are many different types (classes) of medications for high blood pressure; these include beta-blockers, calcium channel blockers, diuretics (medications that increase urine volume), angiotensin converting enzyme inhibitors (ACE inhibitors), and angiotensin receptor blockers (ARBs). Patients may use these medications alone or in combination to control blood pressure. Some of these medications can cause troubles with erections. For example, Inderal (a beta-blocker) and hydrochlorothiazide (a diuretic) cause erectile dysfunction, while calcium channel blockers and ACE inhibitors do not seem to affect erectile function. On the other hand, other medications (such as angiotensin receptor blockers [ARB] including losartan [Cozaar] and valsartan [Diovan]) may actually help with erections. Therefore, if possible, you may benefit from changing your medications, but this requires approval by your prescribing health care provider.

Erectile dysfunction (ED) is the inability to get an erection or to keep one that's firm enough or that lasts long enough for a man to have a satisfying sexual experience. Occasional bouts of ED aren't unusual. In fact, as many as one in five men deal with erectile dysfunction to some degree. Symptoms, of course, are rather obvious. And while age can be a risk factor, so can medication use, health conditions, lifestyle factors (like smoking), and other concerns. Treatment is available and may involve prescriptions, habit changes, or other options.


Proper informed consent with your physician should be performed to understand all risks and benefits of hormonal replacement therapy. Follow-up testosterone (hormone) levels and periodic blood counts as testosterone therapy is associated with a risk of an abnormally high red blood cell count, and prostate checks are necessary for all men on long-term testosterone replacement therapy as there are concerns regarding the risk of testosterone therapy in men with an underlying prostate cancer. The use of testosterone therapy does not cause the development of prostate cancer. Testosterone therapy may increase the size of the prostate and cause urinary troubles.
The placement of a penile prosthesis is typically an outpatient procedure and is typically performed through a single incision. All of the parts of the prosthesis are hidden under the skin. Antibiotics are given to decrease the risk of an infection. A catheter may be left in the penis in some men for a short period. After placement, there will be a time period of healing prior to the ability to use the prosthesis.
Having erection trouble from time to time isn't necessarily a cause for concern. If erectile dysfunction is an ongoing issue, however, it can cause stress, affect your self-confidence and contribute to relationship problems. Problems getting or keeping an erection can also be a sign of an underlying health condition that needs treatment and a risk factor for heart disease.
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