Impotence, also called erectile dysfunction, in general, the inability of a man to achieve or maintain penile erection and hence the inability to participate fully in sexual intercourse. In its broadest sense the term impotence refers to the inability to become sexually aroused; in this sense it can apply to women as well as to men. In common practice, however, the term has traditionally been used to describe only male sexual dysfunctions. Professional sex therapists, while they identify two distinct dysfunctions as forms of impotence, prefer not to use the term impotence per se. Thus, because of its pejorative connotation in lay usage and because of confusion about its definition, the word impotence has been eliminated from the technical vocabulary in favour of the term “erectile dysfunction.”
The link between chronic disease and ED is most striking for diabetes. Men who have diabetes are two to three times more likely to have erectile dysfunction than men who do not have diabetes. Among men with erectile dysfunction, those with diabetes may experience the problem as much as 10 to 15 years earlier than men without diabetes. Yet evidence shows that good blood sugar control can minimize this risk. Other conditions that may cause ED include cardiovascular disease, atherosclerosis (hardening of the arteries), kidney disease, and multiple sclerosis. These illnesses can impair blood flow or nerve impulses throughout the body.
Self-injection of these agents has been of enormous benefit because they represent the most effective way to achieve erections in a wide variety of men who otherwise would be unable to achieve adequate rigid erections. The need for intact nerve pathways to the penile tissue is not needed. The locally injected medication directly relaxes the arteriole vessels and penile cavernosal tissue. Thus, this therapy is not dependent on sexual stimulation.
Erectile dysfunction is common, increases with age, and is associated with multiple common medical problems. A variety of successful therapies exist for men with erectile dysfunction. The success of the therapies can vary with the cause of the erectile dysfunction. A stepwise approach to the treatment of ED allows one to identify the therapy that is effective and the least invasive for the individual. Oral therapy remains the first line medical therapy for ED, however, is effective overall in 40%-80% of individuals. For those individuals who cannot take PDE5 inhibitors or fail from an efficacy or side effect standpoint, a number of alternatives exist. Intracavernous injection therapy is the most effective therapy for ED, however, the invasive nature can affect compliance. Penile prosthesis is a highly effective surgical procedure, but men undergoing placement of a penile prosthesis should be aware of the benefits and risks associated with placement of a penile prosthesis. Other surgical therapies, such as arterial surgery, are rarely needed.
In some cases, ED can be a warning sign of more serious disease. One study suggests ED is a strong predictor of heart attack, stroke, and death from cardiovascular disease. The researchers say all men diagnosed with ED should be evaluated for cardiovascular disease. This does not mean every man with ED will develop heart disease, or that every man with heart disease has ED, but patients should be aware of the link.
If laboratory tests are performed, they would normally start with an evaluation of your hormone status (testosterone or male hormone), particularly if one of your symptoms is low sexual desire (low libido). Blood tests for testosterone should ideally be taken early in the morning because that's when levels are usually at their highest. It is recommended that if the first testosterone level is low to repeat it as testosterone levels can vary. If the testosterone level is low, other blood tests, such a luteinizing hormone and prolactin, can help determine if there is a problem with the pituitary gland.
In comparison, 37% of men who had received external radiotherapy as their primary therapy reported the ability to attain functional erections suitable for intercourse, along with 43% of men who had received brachytherapy as primary treatment. Pretreatment sexual health-related quality of life score, age, serum prostate-specific antigen (PSA) level, race or ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. 
This inflatable penile prosthesis has 3 major components. The 2 cylinders are placed within the corpora cavernosa, a reservoir is placed beneath the rectus muscle, and the pump is placed in the scrotum. When the pump is squeezed, fluid from the reservoir is transferred into the 2 cylinders, producing a firm erection. The deflation mechanism is also located on the pump and differs by manufacturer.
The availability of phosphodiesterase-5 (PDE5) inhibitors—sildenafil, vardenafil, tadalafil, and avanafil—has fundamentally altered the medical management of ED. In addition, direct-to-consumer marketing of these agents over the last 15 years has increased the general public’s awareness of ED as a medical condition with underlying causes and effective treatments.
As with most other organ system in the human body, changes and loss of function is normal consequence of the ageing process. This is also true of the endocrine system, specifically the levels of testosterone production from the Leydig cells of the testicle. Accompanying the decrease in testosterone is a decrease in erections which also has a component in decrease in the blood supply to the penis making erection not as frequent and not as rigid compared with a young man’s erectile function. Although these changes are in itself not life threatening, they can impact a man’s relationship with his partner, and also ED may be a harbinger of other undiagnosed conditions such as coronary artery disease (CAD), hypercholesterolaemia or diabetes mellitus.6
The inflatable type of device consists of cylinders that are implanted in the corpora cavernosa, a fluid reservoir implanted in the abdomen, and a pump placed in the scrotum. The man squeezes the pump to move fluid into the cylinders and cause them to become rigid. (He reverses the process by squeezing the pump again.) While these devices allow for intermittent erections, they have a slightly higher malfunction rate than the silicon rods.
This procedure is usually performed before and after injection of a smooth-muscle-relaxing medication into the penis, which normally should significantly increase the diameter of the penile arteries. The procedure itself is painless. Duplex ultrasonography is most useful in evaluating possible penile arterial disorders, but in those individuals considering surgery for problems with the arteries to the penis, a more invasive study, angiogram, is needed to identify the location of the damaged artery.
The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina; it is now mostly replaced by more precise terms, such as erectile dysfunction (ED). The study of ED within medicine is covered by andrology, a sub-field within urology. Research indicates that ED is common, and it is suggested that approximately 40% of males experience symptoms compatible with ED, at least occasionally. The condition is also on occasion called phallic impotence. Its antonym, or opposite condition, is priapism.
Yohimbine: The main component of an African tree bark, yohimbine is probably one of the most problematic of all natural remedies for ED. Some research suggests that yohimbine can improve a type of sexual dysfunction that is linked with a drug used to treat depression. However, studies have linked yohimbine to a number of side effects, which can include anxiety, increased blood pressure, and a fast, irregular heartbeat. Like all natural remedies, yohimbine should only be used after advice and under supervision from a doctor.
Monitoring erections that occur during sleep (nocturnal penile tumescence) can help you and your doctor to understand if the erectile dysfunction is due to psychological or physical causes. The nocturnal penile tumescence test is a study to evaluate erections at night. Normally men have three to five erections per eight hours of sleep. The test can be performed at home or in a sleep lab. The most accurate way to perform the test involves a special device that is connected to two rings. The rings are placed around the penis, one at the tip of the penis and the other at the bottom (base) of the penis. The device records how many erections occur, how long they last, and how rigid they are. The test is limited in that it does not assess the ability to penetrate.
Induction of erection occurs after stimulation of the cavernous and pelvic nerve plexus. Conversely, stimulation of the sympathetic trunk leads to detumescence. The reflex erectile response requires that the sacral reflex arc remain intact. Tactile and sensory signals are received by the somatic sensory pathways and integrate with parasympathetic nuclei within the sacral spinal cord (S2-4) leading to induction of erection via cholinergic signaling. These reflexogenic erections remain intact with upper motor neuron injuries. Psychogenic erections do not require that the sacral reflex arc remain intact. In a cat models, spinal cord removal below L4/L5 led to absence of a reflexogenic erection but stimulation of the medial preoptic area (MPOA) or placement near a female cat in heat led to erection (5,6). Psychogenic erections occur via induction of central pathways traveling from the brain through the sympathetic chain. Non-penile sensory pathways induced by sight, sound, touch and smell travel through the MPOA to the erection centers within the cord T11-L2, and S2-S4 to induce erections (7). When a sacral lower motor neuron injury is present in men, below T12 these types of erections are more likely to occur (8). Spinal cord lesions above T9 are not associated with psychogenic erections (9). Rigidity of erections is less with psychogenic erections because the thoracolumbar sympathetic outflow may contain a decreased concentration of neurons compared to the parasympathetic outflow from the sacral spinal cord.
Sexual dysfunction and ED become more common as men age. The percentage of complete ED increases from 5% to 15% as age increases from 40 to 70 years. But this does not mean growing older is the end of your sex life. ED can be treated at any age. Also, ED may be more common in Hispanic men and in those with a history of diabetes, obesity, smoking, and hypertension. Research shows that African-American men sought medical care for ED twice the rate of other racial groups.