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.

An erection occurs due to hydraulic effects due to blood entering and being retained in sponge-like bodies inside the penis. Duringintercourse , 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 ) anddrug 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 silenceand 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.

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 .

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.

Causes

• Neurogenic Disorders ( spinal cord and brain injuries , nerve disorders such as Parkinson’s disease , Alzheimer’s disease , multiple sclerosis , and stroke .)
• Hormonal Disorders ( pituitary gland tumor ; low level of the hormone testosterone).
• Arterial Disorders ( peripheral vascular disease , hypertension ; reduced blood flow to the penis).
• Cavernosal Disorders ( Peyronie’s disease .)
• Nonphysical causes: Mental disorders ( clinical depression , schizophrenia , substance abuse , panic disorder , generalized anxiety disorder , personality disorders or traits.), psychological problems, negative feelings.
• Surgery ( radiation therapy , surgery of the colon , prostate, bladder , or rectum may damage the nerves and blood vessels involved in erection. Prostate and bladder cancer surgery often require removing tissue and nerves surrounding a tumor, which increases the risk for impotence.
• Aging .
• Lifestyle: alcohol and drugs, obesity , cigarette smoking (Incidence of impotence is approximately 85 percent higher in male smokers compared to non-smokers. Smoking is a key cause of erectile dysfunction. Smoking causes impotence because it promotes arterial narrowing . See also Tobacco and health .
• Other disorders.

Excessive alcohol use has long been recognised as one cause of impotence, leading to the euphemism " brewer’s droop," or " whiskeydick;" 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.

Some evidence suggests that smaller penis size is associated with erectile dysfunction.

Diagnosis

Clinical Tests Used to Diagnose ED

Duplex ultrasound

Duplex ultrasound is used to evaluate blood flow, venous leak, signs of atherosclerosis, and scarring or calcification of erectile tissue. Injecting prostaglandin , a hormone-like stimulator produced in the body, induces erection. Ultrasound is then used to see vascular dilation and measure penile blood pressure . Measurements are compared to those taken when the penis is flaccid.

Penile nerves function

Tests such as the bulbocavernosus reflex test are used to determine if there is sufficient nerve sensation in the penis. The physician squeezes the glans (head) of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the latency between squeeze and contraction by observing the anal sphincter or by feeling it with a gloved finger inserted past the anus. Specific nerve tests are used in patients with suspected nerve damage as a result of diabetes or nerve disease.

Nocturnal penile tumescence (NPT)

It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge. (It should be noted that a significant proportion of men who have no sexual dysfunction nonetheless do not have regular nocturnal erections. Thus presence of NPT tends to signify physically functional systems, but absence of NPT may be ambiguous and not rule out either cause.)

Penile biothesiometry

This test uses electromagnetic vibration to evaluate sensitivity and nerve function in the glans and shaft of the penis. A decreased perception of vibration may indicate nerve damage in the pelvic area, which can lead to impotence.

Penile Angiogram

Invasive test - allows visualization of the circulation in the penis and is used during the repair of a priapism .

Dynamic Infusion Cavernosometry

(Abbreviated DICC) technique in which fluid is pumped into the penis at a known rate and pressure. It gives a measurement of the vascular pressure in the corpus cavernosum during an erection. To do this test, a vasodilator like prostaglandin E-1 is injected to measure the rate of infusion required to get a rigid erection and to help find how severe the venous leak is.

Corpus Cavernosometry

Cavernosography measurement of the vascular pressure in the corpus cavernosum. Saline is infused under pressure into the corpus cavernosum with a butterfly needle, and the flow rate needed to maintain an erection indicates the degree of venous leakage. The leaking veins responsible may be visualised by infusing a mixture of saline and x ray contrast medium and performing a cavernosogram.

Digital Subtraction Angiography

In DSA, the images are acquired digitally. The computer creates a mask from lower-contrast x-rays of the same area and digitally isolates the blood vessels (this is done manually through darkroom masking with traditional angiography).

Magnetic resonance angiography (MRA)

This is similar to magnetic resonance imaging . Magnetic resonance angiography uses magnetic fields and radio waves to provide detailed images of the blood vessels. Doctors may inject a "contrast agent" into the patient’s bloodstream that causes vascular tissues to stand out against other tissues. The contrast agent provides for enhanced information regarding blood supply and vascular anomalies. Aside from the IV used to introduce the contrast material into the bloodstream, magnetic resonance angiography is noninvasive and painless.

Treatment

1. Oral treatment

2. Vacuum device

Please see main article penis pump

3. Hormone treatment

4. Surgery

5. Counselling

6. Herbal and other alternative treatments