Encyclopedia
| Erectile dysfunction
Encyclopedia
|
| Tutorials | Encyclopedia | Dictionary | Directory |
|
Erectile dysfunction
Erectile dysfunction (ED or (male) impotence) is a sexual dysfunction characterized by the inability to develop or maintain an erection of the penis sufficient for satisfactory sexual performance.[1] An erection occurs due to hydraulic effects due to blood entering and being retained in sponge-like bodies inside the penis. During intercourse, the process is initiated when sexual arousal is transmitted from the brain to nerves in the pelvis. There are various and often multiple underlying causes, some of which are treatable medical conditions. The most important organic causes are cardiovascular disease and diabetes, neurological problems (for example, trauma from prostatectomy surgery), hormonal insufficiencies (hypogonadism) and drug side effects. It is important to realise that erectile dysfunction can signal underlying risk for cardiovascular disease. There is often a contributing and complicating and sometimes a primary psychological or relational problem. Psychological impotence is where erection or penetration fails due to thoughts or feelings (psychological reasons) rather than physical impossibility; this can often be helped. Notably in psychological impotence, there is a strong response to placebo treatment. Erectile dysfunction, tied closely as it is to cultural notions of potency, success and masculinity, can have severe psychological consequences. There is a strong culture of silence and inability to discuss the matter. In reality, it has been estimated that around 1 in 10 men will experience recurring impotence problems at some point in their lives.[2] Besides treating the underlying causes and psychological consequences, the first line treatment of erectile dysfunction consists of a trial of PDE5 inhibitor drugs (the first of which was sildenafil or Viagra). In some cases, treatment can involve prostaglandin tablets in the urethra, intracavernous injections with a fine needle into the penis that cause swelling, a penile prosthesis, a penis pump or vascular reconstructive surgery.[3] The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina. It is now mostly replaced by more precise terms. The study of erectile dysfunction within medicine is covered by andrology, a sub-field within urology.
Overview and symptomsErectile dysfunction is characterized by the regular or repeated inability to obtain or maintain an erection. There are several ways that erectile dysfunction is analyzed:
Erection problems are very common. The Sexual Dysfunction Association estimates that 1 in 10 men in the UK have recurring problems with their erections at some point in their life.[2] PathophysiologyPenile erection is managed by two different mechanisms. The first one is the reflex erection, which is achieved by directly touching the penile shaft. The second is the psychogenic erection, which is achieved by erotic or emotional stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic system of the brain. In both conditions, an intact neural system is required for a successful and complete erection. Stimulation of penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. Additionally, adequate levels of testosterone (produced by the testes) and an intact pituitary gland are required for the development of a healthy erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems. Restriction of blood flow can arise from impaired endothelial function due to the usual causes associated with coronary artery disease, but can also be caused by prolonged exposure to bright light. Causes
A few causes of impotence may be iatrogenic (medically caused). Various antihypertensives (medications intended to control high blood pressure) and some drugs that modify central nervous system response may inhibit erection by denying blood supply or by altering nerve activity. Surgical intervention for a number of different conditions may remove anatomical structures necessary to erection, damage nerves, or impair blood supply. Complete removal of the prostate gland or external beam radiotherapy of the gland are common causes of impotence; both are treatments for prostate cancer. Some studies have shown that male circumcision may result in an increased risk of impotence,[13][14] while others have found no such effect,[15][16][17] and another found the opposite.[18] Excessive alcohol use has long been recognised as one cause of impotence, leading to the euphemism "brewer's droop," or "whiskey dick;" Shakespeare made light of this phenomenon in Macbeth. A study in 2002 found that ED can also be associated with bicycling. The number of hours on a bike and/or the pressure on the penis from the saddle of an upright bicycle is directly related to erectile dysfunction.[19] Some evidence suggests that smaller penis size is associated with erectile dysfunction.[20] DiagnosisMedical diagnosisThere are no formal tests to diagnose erectile dysfunction. Some blood tests are generally done to exclude underlying disease, such as diabetes, hypogonadism and prolactinoma. Impotence is also related to generally poor physical health, poor dietary habits, obesity, and most specifically cardiovascular disease such as coronary artery disease and peripheral vascular disease. A useful and simple way to distinguish between physiological and psychological impotence is to determine whether the patient ever has an erection. If never, the problem is likely to be physiological; if sometimes (however rarely), it could be physiological or psychological. The current diagnostic and statistical manual of mental diseases (DSM-IV) has included a listing for impotence. Clinical Tests Used to Diagnose ED
TreatmentTreatment depends on the cause. Testosterone supplements may be used for cases due to hormonal deficiency. However, the cause is more usually lack of adequate penile blood supply as a result of damage to inner walls of blood vessels. This damage is more frequent in older men, and often associated with disease, in particular diabetes. Treatments (with the exception of testosterone supplementation, where effective) work on a temporary basis: they enable an erection to be attained and maintained long enough for intercourse, but do not permanently improve the underlying condition. There are different treatments available:[22]
3 different tablets are currently available from the doctor and these work when there is sexual stimulation. Depending on the treatment, it will need to be taken 20 minutes to 1 hour before sex and the period of time over which it works can vary between 3 hours and up to 36 hours. This can be injected into the penis or inserted using a special applicator - usually just before sexual intercourse. Alprostadil has also bcome available in some countries as a topical cream (under the brand name Befar),[23] and preliminary studies have shown a clinical efficacy of up to 83%.[24] It has an onset of action of 10-15 minutes and its effects can last over 4 hours.
These work by placing the penis in a vacuum cylinder device. [25] The device helps draw blood into the penis. A ring at the base of the penis help maintain the erection.[25] This type of device is sometimes referred to as penis pump and may be used just prior to sexual intercourse.
It is rare, but some men receive hormones for their erection problem. This does depend on the cause of the problem as well as other factors.
Often, as a last resort if other treatments have failed, the most common procedure is prosthetic implants which involves the insertion of artificial rods into the penis.[26]
Counselling is often a consideration, both where a psychological cause is suspected or must be ruled out, or to assist in management of any distress. ED can in many cases be treated by drugs taken orally, injected, or as penile suppositories. These drugs increase the efficacy of NO, which dilates the blood vessels of corpora cavernosa. When oral drugs or suppositories fail, injections into the erectile tissue of the penile shaft are extremely effective but occasionally cause priapism. When pharmacological methods fail, a purpose-designed external vacuum pump can be used to attain erection, with a separate compression ring fitted to the penis to maintain it. These pumps should be distinguished from other "penis pumps" (supplied without compression rings) which, rather than being used for temporary treatment of impotence, are claimed to increase penis length if used frequently, or vibrate as an aid to masturbation. More drastically, inflatable or rigid penile implants may be fitted surgically. Implants are irreversible and costly. All these mechanical methods are based on simple principles of hydraulics and mechanics and are quite reliable, but have their disadvantages. In a few cases there is a vascular problem which can be treated surgically. Uncontroversial treatments
One of the forms of phophodiesterase is termed PDE5. The prescription PDE5 inhibitors sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) are prescription drugs which are taken orally. They work by blocking the action of PDE5, which causes cGMP to degrade. CGMP specific phosphodiesterase type 5 causes the smooth muscle of the arteries in the penis to relax, allowing the corpus cavernosum to fill with blood. (Specific devices are mentioned for information only; mention should not be taken as endorsement).
Controversial and unapproved treatments
Other treatment methodsZincZinc is known to help prevent the conversion of testosterone to estradiol, and testosterone is essential for proper erectile function and the synthesis of sperm (testosterone deficiency is a primary contributor in many cases of erectile dysfunction).[34][35][36][37][38] Moreover, zinc levels have been found to be significantly reduced in both chronic bacterial prostatitis (CBP) and non-bacterial prostatitis (NBP). Many doctors and nutritionalists recommend zinc for prostate or erectile problems.[39][40][41] Zinc is best taken in lozenge form, as in tablet form, zinc is difficult to absorb, and can irritate the stomach lining.[42] HistoryThe earliest attempts at treating erectile dysfunction date back to Muslim physicians and pharmacists in the medieval Islamic world. They were the first to prescribe medication for the treatment of this problem, and they developed several methods of therapy for this issue, including a single-drug therapy method where a drug was prescribed and a "combination method of either a drug or food." Most of these drugs were oral medication, though a few patients were also treated through topical and transurethral means. Erectile dysfunctions were being treated with tested drugs in the Islamic world since the 9th century until the 16th century by a number of Muslim physicians and pharmacists, including Muhammad ibn Zakar?ya R?zi, Thabit bin Qurra, Ibn Al-Jazzar, Avicenna (The Canon of Medicine), Averroes, Ibn al-Baitar, and Ibn al-Nafis (The Comprehensive Book on Medicine).[43] Dr. John R. Brinkley initiated a boom in male impotence cures in the US in the 1920s and 1930s. His radio programs recommended expensive goat gland implants and "mercurochrome" injections as the path to restored male virility, including operations by surgeon Serge Voronoff. After the Kansas State Medical Board revoked his medical license and the Federal Radio Commission refused to renew his radio license (both in 1930), Brinkley moved his operations just over the Texas border to Mexico where he opened a medical clinic and broadcast advertisements into the US from a border blaster radio station. Surgeons began providing patients with inflatable penile implants in the 1970s. Modern drug therapy for ED made a significant advance in 1983 when British physiologist Giles Brindley, Ph.D. dropped his trousers and demonstrated to a shocked American Urological Association audience his phentolamine-induced erection. The drug Brindley injected into his penis was a non-specific vasodilator, an alpha-blocking agent, and the mechanism of action was clearly corporal smooth muscle relaxation. The effect that Brindley discovered established the fundamentals for the later development of specific, safe, orally-effective drug therapies.[44] Reference: See alsoReferencesExternal links
ca:Disfunció erèctil cs:Erektilní dysfunkce da:Impotens de:Erektile Dysfunktion es:Disfunción eréctil eo:Impotenteco fr:Impuissance sexuelle id:Disfungsi ereksi it:Disfunzione erettile he:???-????? la:Impotentia erecti lt:Impotencija ms:Lemah tenaga batin nl:Impotentie no:Erektil dysfunksjon ja:???? pl:Impotencja pt:Disfunção erétil ru:?????????? sl:Erektilna disfunkcija sr:??????????? fi:Erektiohäiriö sv:Impotens vi:Li?t d??ng yi:???????? ?????????? zh:?????? Source: Wikipedia | The above article is available under the GNU FDL. | Edit this article
|
|
top
©2008-2009 TutorGig.com. All Rights Reserved. Privacy Statement
