Erectile Dysfunction

Definition and Incidence

Erectile dysfunction (ED) is defined as the persistent or recurrent inability of man to achieve and/or maintain a sufficient penile erection, both for his own and for the needs of the partner, to lead and manage a successful sexual intercourse. This condition can occur occasionally and without inducing psychological problems or management, but when it is repeated several times and the dysfunctional defect becomes more important for quality and/or quantity then a whole series of problems related to it are activated. Normally it is distinguished:

  • Primary Erectile dysfunction – If the man has never been able to achieve or sustain erection due to psychological causes and/or biological
  • Secondary Erectile dysfunction – If man who previously could achieve and sustain erections, is no longer able to do so, for organic causes in 90% of cases

The persistent ED is an uncommon problem under 40 years of age. Generally the incidence of ED is about 10% in the Western population, but it reaches 50% in the age between 40 and 70 years, so that about 65% of men aged 70 presents problems of ED, increase mainly due to vascular disorders and that occurs with about 10 years earlier in diabetic men. Unfortunately, the issue is adequately addressed by only a very small part of the men involved, at all ages and especially in young men, both to minimize the problem of fear or shame. This attitude often leads to a worsening of the overall picture that instead could be solved quite easily, if not always quickly, after the accurate diagnosis of the causes.


Numerous physical and psychological factors are involved in normal erectile function, including neurological, vascular and hormonal factors. More simply, the underlying causes of ED can be:

  • Organic
    ED is caused by an alteration of the anatomical structure or physiological functioning of the systems involved in the erection process. The most common organic causes are those that affect the vascular system of the erection (atherosclerosis of the arteries of the penis, linked to harmful lifestyles such as smoking, physical inactivity, obesity and/or chronic conditions such as hypertension, diabetes, hyper cholesterolemia that prevents the increase in blood flow necessary to bring and maintain an erection); endocrine diseases, in particular testosterone deficiency; neurological and psychiatric disorders, in particular depression and traumatic injuries of the nerve pathways that carry erectile signals to the penis, which may occur, for example, as a result of spinal trauma of the column or following surgery on organs of the abdomen such as the bladder, prostate, rectum and abdominal aorta.
  • Psicogene
    In the absence of a detectable organic cause, the ED is caused by a central inhibition of the mechanisms of erection, or by a psychological alteration, dependent by cognitive and emotional processes.
  • Mixed
    When both factors, psychogenic and organic coexist.

In the majority of patients with ED, there is a combination of organic and psychogenic factors. However it is important to note that the etiological classifications are relatively simple. Indeed, the presence of an organic alteration in case of ED does not exclude concomitant psychological causes. On the other hand the non-detection of an organic cause not confirm, by itself, the exclusively psychogenic origin of ED.

Anatomy of the Penis

The penis consists of a cylindroid part, the body, and a conoid part, the glans. The main structure of both is vascular type, which is a network of vessels widely communicating between them in which the blood volume and the rigidity of the covering sheath constitute the basic conditions for the erection. The body of the penis consists of two dorsolateral cylindrical bodies, called cavernous bodies (corpora cavernosa), enveloped by a thick sheath of fibrous tissue little elastic or tunica albuginea, and a mid-ventral cylindrical body, called spongious body (corpus spongiosum), in which is placed the penile or spongy urethra. The fibers of the tunica albuginea surrounding the cavernous bodies and join to form a perforated septum that allows these bodies to operate as a single unit .
The cavernous bodies and spongy body of the penis are surrounded by a deep fibrous tissue, Buck’s fascia. The cavernous spongiform tissue form a network of interconnected cavernous spaces, called sinusoidal or lacunar spaces. The epithelial vascular cells cover the cavernous spaces separated by trabeculae, constituted by bundles of smooth muscle fibers, with an extracellular matrix (elastin, collagen, and fibroblasts).
The cavernous bodies are the erectile elements dysfunction, while the urethra, the channel for urine and semen emission, is therefore connected to the bladder and the ejaculatory ducts. The glans is the terminal part of the penis, and has at its top the urethral opening, the meatus which serves for the emission outside of urine and sperm. The skin, with a high elasticity, covers the whole body to the third distal, almost to the glans, then folds up to form the foreskin, which more or less completely covers the glans, and whose vertex is connected ventrally by the frenulum or fillet. The penis is primarily vascularized by internal pudendal artery, which branches into perineal artery and penile artery. The penile artery then divides into the bulbar, urethral, dorsal spongy and cavernous arteries. The cavernous artery enters into the cavernous bodies and runs along the penile body, where it divides into many branches called helicine arteries which open in the cavernous spaces . The blood drains from the penis through the superficial, intermediate and deep veins. These latter drain the blood from the cavernous bodies and the spongious bodies. On the basis of sensory stimuli increases the flow of blood through the cavernous arteries and helicine arteries and this leads to erection.

Physiology of erection

The mechanism of erection is a hemodynamic event that involves both Central Nervous System vascular and the vascular system. It is one of the most sophisticated and complex mechanisms, as well as one of the most perfect of the human body. In fact it provides that a double series of impulses that come from two different areas of the body, the limbic system of the brain, where instinctive impulses arise, and the area of the genitals where arise the sensitive impulses, go simultaneously to activate and deactivate the erection center located in the spinal cord. The stimuli coming from the brain arise from a series of commands coming from the hypothalamus from senses of smell and sight, while those coming from genital apparatus are essentially tactile. While instinctive impulses that are the basis of libido arise from the brain to the centers lumbar and sacral of erection, the other stimuli arise from the nerve fibers connected to the external genitalia, in coordination with each other: in the absence of stimuli by an area, these are compensate by those of the other area.
The physical and psychological stimuli converge on the center of the erection so then move on to the cavernous bodies of the penis, through a circuit that triggers the increase of blood flow (arterial) to the penis and decreases the outflow (venous) from the penis. The two penile arteries carry blood to the two cavernous bodies, while the spongious artery carries it to the penis, so that the increase in the amount clog up the vascular network of the cavernous bodies and glans pumping them: rigidity is due to the delicate balance that is achieved between the increased pressure in the vascular network and the elastic stiffness of the tunica albuginea that covers it. The pressure is also supported by the partial closure for compression and contraction of smooth muscle fibers near the valves of the veins. Simultaneously with the relaxation of the cavernous arteries is also the relaxation of smooth muscle of the cavernous bodies. An adequate blood flow to the penis is therefore the key to making this process work properly.

Biochemical mechanisms of erection

Current knowledge indicates that the relaxation of smooth muscles of the cavernous bodies and the activity of the vascular network necessary for penile erection are also supported by the release of molecules with vasodilatotory actvity. Neurotransmitters are emitted along the circuits of activation and deactivation of the erectile response of the penis; so depending on which of the two activities dominates, it will activate or deactivate the erectile process. Under physiological conditions, one of the main positive mediators of the erectile phenomenon is the nitric oxide (NO), a neurotransmitter originally called endothelium derived releasing factor from the, synthesized from arginine and released from nerve terminals NANC (non- adrenergic non cholinergic), in response to sexual stimulation, and then it spread in the smooth muscle of the cavernous bodies. After spreading to the muscle cells, NO activates the cytosolic enzyme guanylate cyclase, which synthesizes a second messenger, the cyclic guanosine monophosphate (cGMP) from GTP. This intracellular mediator (cGMP) allows the relaxation of smooth muscles of the cavernous bodies, leading to the appearance of penile tumescence and finally erection. The cGMP is then usually hydrolysed by nucleotidic cyclic isoenzymes, called phosphodiesterases (PDEs), which are located in various tissues. In the cavernous body of man, the predominant isozyme of cGMP-specific PDE is the type 5 (PDE5) or 5-phosphodiesterase, which catalyzes the conversion of cGMP to GMP thus ending this activator signal and deactivating the process of vasodilation. Therefore the erectile process is the result of several and very delicate erectile mechanisms that can be reversed also quickly enable or disable it.

Pathophysiology of erection

The relaxation of the smooth muscle of the cavernous body and penile erection depend on a delicate balance between the effects of vasoconstrictors and vasodilators factors. To bring the flaccid penis, tonically contract in the erection state, it is necessary that the relaxation of the smooth muscle of the cavernous body have to exceed a certain threshold level. It has been shown that the basic defect in patients with erectile dysfunction can be, regardless of etiology, an imbalance between the contraction and the ability to smooth muscle relaxation in the cavernous body. If the base tone of smooth muscle of the cavernous body is too high, the maximum relaxation level may not be sufficient to allow the increase of the blood flow required for a normal erection. If the threshold level of smooth muscle relaxation is not reached or is maintained, the resistance to venous outflow will be insufficient. For this reason you can have erections with different degrees of rigidity.

Treatment of Erectile Dysfunction

The therapeutic treatment of ED can be divided into different solutions and must always predict the possible therapies for the organic type related diseases on other organs, genital or otherwise, or other districts: these will be resolved or rebalanced before or simultaneously with the specific treatment for erectile dysfunction.
The general approach should be to advise the patient to reduce smoking and alcohol consumption. The control of diabetic patients should be followed carefully, considering the possibility of changing the drug therapy in progress, even if the transition from one to another antihypertensive drug rarely used to improve erectile dysfunction. It possible to prescribe testosterone in older men with isolated androgen deficiency proven, particularly in patients with impaired libido. However, it is firstly need to exclude the presence of prostate cancer. Young patients with androgen deficiency and those with hyperprolactinaemia should be addressed to an endocrinologist.

Use of Phytotheray

The use of phytotherapeutic remedies, well selected and properly prepared, it is often useful to integrate drug therapy or as a consolidation treatment when the drug therapy is not necessary. It is important that the phytotherapeutic remedies or herbal medicines are of high quality and adequate preparation. The choice, composition and the dosage must be determined by a doctor or urologist phytotherapist. Among the main phytotherapeutic remedies normally used for the treatment of ED there are: Asian Ginseng, Ginkgo Biloba, Maca, Muira Puama, Guaranà, Damiana, Catuaba.