Erectile dysfunction

Updated 15 May 2015

Erectile dysfunction (impotence)

Erectile dysfunction is the inability to get or maintain an erection.



  • Erectile dysfunction (impotence) is the inability to get or maintain an erection that is sufficient to ensure satisfactory sex for both partners.
  • Erectile dysfunction can have a physical or psychological cause, but in the majority of cases it is physical.
  • Most men experience occasional problems with obtaining an adequate erection, but this should not be a cause for concern.
  • Erectile dysfunction can be treated at any age.
  • Treatment options include improving lifestyle, sex therapy, drug therapy, injection therapy, vacuum pumps and surgery.

What is erectile dysfunction?

Erectile dysfunction (previously called impotence) is the inability to get or maintain an erection that is sufficient to ensure satisfactory sex for both partners. This problem can cause significant distress for couples. Fortunately more and more men of all ages are seeking help, and treatment has advanced rapidly. The enormous demand for “anti-impotence” drugs suggests that erection problems may be more common than was previously thought.

Erectile dysfunction should be distinguished from other male sexual functioning difficulties, sometimes erroneously referred to as impotence, such as premature ejaculation, male orgasmic disorder (delay or absence of orgasm) and hypoactive sexual desire disorder (lack of or diminished sexual interest or desire).

Men with erectile dysfunction may or may not suffer from these other problems.

Erectile dysfunction can occur at any age. Occasional episodes are considered normal.

How common is ED?

Current statistics are not available for South Africa, but in America about 10% of men are believed to be affected.

Incidence rises with age: about 5% of men at the age of 40 and between 25 and 40% of men at the age of 65 suffer from erectile dysfunction, and the percentage grows to 70% as men reach 80.

As men age, they typically report some loss of sexual desire as well, although neither loss of desire nor erectile dysfunction is an unavoidable feature of ageing.

Many erection problems can be prevented or even reversed by a more relaxed approach to sex and by rediscovering sensuality.

Sexual intimacy is a form of communication. If you and your partner talk about your lovemaking, it will help reduce your stress and anxiety so that your sexual activity may become more relaxed. Many people avoid talking about problems in their sexual relationship.

It may gradually become more difficult to get and maintain an erection as you grow older, however foreplay and the right environment can increase your ability to have an erection, regardless of age.

Causes of ED

A firm erection is the result of a whole series of psychological and physical events.

If a problem occurs at any step in the process, the erection may be absent, insufficient or short-lived. There is therefore a range of possible causes of erectile disorder. These may include vascular (related to the blood vessels and spongy tissue in the penis), neurogenic (nerves supplying the penis), hormonal, drug-related causes and psychological factors. Most erection problems are due to a combination of these factors. Until the early 1990s, most cases of erectile dysfunction were thought to be of psychological origin, but new research has shown that the reverse is true.

How does a successful erection work?
An erection begins with sensory and mental stimulation.

Impulses from the brain travelling down the spinal column and impulses from the nerves in the penis relax smooth muscles in two spongy cylinders that run the length of the penis, parallel to the urethra (the conduit for urine and semen). When the impulses cause the muscles to relax, blood flows into spaces in the spongy tissue and this pressure makes the penis swell.  A membrane surrounding the cylinders helps to trap the blood in the penis and maintain the erection.

The penis returns to its flaccid state if the muscles contract, stopping the inflow of blood and opening outflow channels.

An erection problem can occur if any of the events in this sequence are disrupted: the problem may involve mental processes, nerve impulses or responses in muscles, fibrous tissue as well as veins and arteries in the penis.

Physical causes
The most common cause of erectile dysfunction is damage to arteries, smooth muscles and fibrous tissues.
  • Problems with the blood vessels (vascular problems) make up 48% of erection problems.
  • Problems with the nerves (neurological problems): 14%
  • Problems with the structure of the penis or surrounding tissues: 3%
These problems can in turn be caused by a variety of factors:
  • Disease: illnesses account for 70% of erectile dysfunction. These may include diabetes, kidney disease and multiple sclerosis. Atherosclerosis or "hardening of the arteries" can prevent adequate blood from entering the penis.
  • Injury to the penis, spinal cord, prostate, bladder or pelvis: such injury can be the result of sports or car accidents, or even riding on hard bicycle seats (almost always temporary).
  • Complications of surgery or radiation (e.g. for prostate cancer): these can interfere with nerve impulses or blood flow to the penis. When the nervous system cannot transmit arousal signals, or when the blood vessels in the penis cannot fill or stay filled with blood, you cannot have an erection.
  • Side effects of common medication: these include drugs taken for high blood pressure, anti-depressants, anti-histamines, tranquillisers, appetite suppressants and the ulcer drug cimetidine.
  • Substance abuse: chronic use of alcohol, marijuana or other drugs often causes impotence, which may be aggravated by decreased sexual drive. Excessive tobacco use can also block penile arteries.
  • Hormonal factors, such as low testosterone levels.
  • Erection problems in men over the age of 50 are more likely to have physical causes.

Psychological causes
Psychological problems, such as anxiety, interfere with the erection process by distracting the man from things that would normally arouse him. These problems cause between 10 and 40% of erectile dysfunction. Even in cases where the underlying problem is physical, these factors can play an important secondary role, for example when a man who has had some erectile difficulty starts to anticipate and fear sexual failure. As a result, psychological factors play some causal role in at least 80% of cases of erectile dysfunction.

These factors include:
  • Depression: erectile dysfunction is twice as likely among men suffering from depression as it is among those without depressive symptoms.
  • Relationship problems: a man who loses sexual interest in or desire for a particular partner may develop erection problems.
  • Anxiety and stress, including those caused by major life changes.
  • Grief and other reactions to major loss: recently widowed men may have erection problems.
  • Low self-esteem.
  • Guilt because of extramarital affairs, especially if sexually transmitted diseases are feared.
  • Psychological causes – more prominent in younger men.

What are the symptoms?

  • Inability to have an erection at any time, either alone or with a sexual partner.
  • Inability to maintain an adequate erection until completion of the sexual activity.

If erectile failure:
  • Is only temporary or occasional, the problem is probably not serious; all men go through periods of erectile problems.
  • Develops gradually and persistently, a physical cause is likely; this is generally the case with chronic impotence.
  • Develops abruptly but you still have early-morning erections and are able to have an erection while masturbating, the problem probably has a psychological cause.
Sexual interest and desire may be normal or impaired, as may be your ability to have an orgasm and to ejaculate.

In general
When erection problems become persistent, they can affect your self-image and sexual life. If you have had persistent erection problems, "performance anxiety" can worsen your problem. A man who cannot have satisfactory intercourse may still have a strong sex drive, which can be frustrating. In some cases, for example where the problem is the result of transient factors such as a major life change or relationship difficulty, erection problems may clear up spontaneously once the causes have disappeared. In other cases, particularly where there is more than one cause and the problem has become a source of great distress, spontaneous recovery is less likely.

Fortunately, many of the physical and psychological factors that cause erection problems respond to treatment.

Risk factors for ED

The following factors increase the risk of having a problem with the blood vessels or nerves that are needed to have normal erections:
  • Diabetes. Between 35 and 50% of men with diabetes have erection problems. About half of men with diabetes develop erection problems within five years of being diagnosed with diabetes.
  • High blood pressure, blood vessel disease, stroke.
  • High cholesterol and low HDL (high density lipoproteins) cholesterol (a "good" form of cholesterol that protects you against heart disease).
  • Low levels of the hormones needed for the normal development and function of the sex organs (hypogonadism). This especially applies to testosterone, the “male hormone”. Thyroid problems may also increase the risk of erection problems.
  • Multiple sclerosis, Parkinson’s disease, spinal cord injury and other neurological diseases.
  • Injury to the penis or pelvic region.
  • Pelvic surgery or radiation treatment.
  • Use of drugs to treat high blood pressure or depression, diuretics, or tranquillisers.
  • Chronic alcohol or recreational drug abuse, cigarette smoking.

The following factors increase the risk of a psychological cause of erection problems:

  • Depression
  • Anxiety or stress
  • Relationship problems
  • Recent major life change (birth of a child, retirement, job change, loss or death of a partner, divorce, marriage)
  • Restless legs syndrome. Recent studies show higher incidence of ED in men with this condition.


Determining the cause of erection problems is often the key to reversing them. It can be complicated to make an exact diagnosis, since both physical and psychological factors are often involved.

As part of the initial evaluation, your doctor may do the following:

  • History taking. He /she should ask you about your lifestyle, your diet, habits (smoking, alcohol, recreational drugs), whether you have sufficient exercise, rest.  How much stress do you have, medications you take, details regarding your sex life. This will enable him to review risk factors.
  • A complete physical exam including measurements of vital signs, chest, heart, abdomen and genitalia.  A rectal and prostate exam may be necessary.  Special attention will be focused on the penis and its nerve supply. Abnormal secondary sex characteristics, such as loss of armpit or pubic hair, can suggest problems in the endocrine system affecting hormone levels. A circulatory problem might be indicated by, for example, an aneurysm in the abdomen (such as disease of the large artery, the aorta, which supplies blood to the abdomen and lower limbs).
  • Routine lab tests. These include blood counts, urine analysis, lipid profile and measurement of liver enzymes and kidney function. If sexual desire is low, the levels of testosterone in the blood may be measured to determine if there are any endocrine abnormalities.
  • Nocturnal penile tumescence testing (rigiscan). This test, which monitors if you have erections while asleep, can often help to determine whether the cause is predominantly psychological or physical. Physically healthy men have involuntary erections in their sleep; if these occur, the cause is more likely to be psychological. However, these tests are not completely reliable and have not been standardised. These tests are only required in severe erectile dysfunction and are offered by specialist clinics. The modern era of effective oral treatment has reduced the indications for penile tumescence testing drastically.
  • Tests to evaluate penile arteries and veins. This includes the use of medication to assess erections, ultrasound and angiography (a radiographic technique for examining the anatomy of a blood vessel), also not commonly performed these days.
  • Extensive nervous system tests. These are not standardised and are generally done only at major medical centres.
  • Psychological evaluation. This may be recommended when a major psychological cause is suspected.

You and your doctor will use the results of the examination and tests to develop a treatment plan that may include medication, other non-surgical treatments or surgery.

When to see a doctor

Consult your GP or urologist if persistent erectile dysfunction is present. Even if no other symptoms are present, it might be an indication of an underlying disease, e.g. cardiovascular disease, low testosterone or medication side-effects.

Watch and wait if you’ve only had a single episode of an erection problem. It could be a temporary, easily reversible problem. Do not expect it to recur. If possible, forget about it and anticipate a more successful experience next time. Discuss the problem and fears or anxieties with your partner. However, if you are having persistent, bothersome erection problems, talk to your doctor.

Men wait an average of five years before seeking treatment for erection problems and this is unnecessary.

Seek care immediately if an erection lasts longer than four hours after you use an erection-producing medication. This problem, called priapism, can cause permanent damage to your penis.

See a health professional who has experience and interest in dealing with erection problems. Urologists are specialists in this area and your GP will be able to refer you to one. There are also highly qualified sexologists who deal with complex sexual difficulties and couple issues.


Treatment for erectile dysfunction depends on whether the problem is caused by psychological or physical factors, or a combination of these. Even if erectile dysfunction has a physical cause, it often has adverse psychological effects that make the problem worse and treatment more complicated.

The following treatments have a reasonable chance of success:

  • Improving lifestyle, giving up unhealthy habits/behaviour
  • Treatment to modify reversible causes
  • Change in current medication, e.g. blood pressure medication
  • Hormone replacement with male hormone testosterone
  • Corrective surgery in case of penile curvature (Peyronie’s disease) and trauma

First-line treatment

  • Oral treatment
  • Vacuum constriction devices
  • Psychosexual therapy

Second-line treatment
  • Intra-cavernosal injection therapy

Third-line therapy
  • Surgery (prosthesis)

The least invasive treatment should be considered first. Non-surgical treatments work for 60 to 70% of men and may make surgery unnecessary. Although treatments like injections are effective more than 80% of the time, up to 60% of men may eventually drop out of treatment. Sometimes, once men can get an erection again, they realise they have overestimated its importance in their relationships. They may decide that the nuisance or cost of the treatment is not worth the effort.

Erectile dysfunction, whether caused by blood vessels (vascular), hormonal, nervous system, or psychological problems, can be treated with a range of prescription drug therapies.

Oral medication
  • Increase of blood flow into the penis (erection-producing medications)
  • Reduction of performance anxiety by ensuring successful erections
  • Adjustment or replacement of medication taken for other conditions. If such drugs affect your erections, your doctor may review them in an attempt to reduce side effects. Never adjust your dosage without consulting your doctor.
  • Correction of abnormal hormone levels through testosterone replacement therapy. Abnormal hormone levels, however, are a rare cause of erection problems.

Sildenafil (Viagra)
The oral drug sildenafil, sold under the trade name Viagra, has been a media sensation. Since its introduction in America in April 1998 there has been unprecedented demand and it earned its manufacturers, Pfizer, global revenues of about $800m in 1998. The diamond-shaped blue tablet is taken about 60 minutes before sexual activity. Sildenafil works by inhibiting an enzyme called 5-phosphodiesterase, thus increasing the levels of a substance called cyclic GMP. It is a powerful dilator of blood vessels in the penis, leading to the inflow of blood and an erection under stimulating circumstances.

There have been reports of Viagra users dying from heart attacks, but these attacks were not thought to be related to the drug. A certain percentage of heart attacks will occur during strenuous activity. Nevertheless, the manufacturers have issued warnings to individuals with cardiovascular disease. Caution is specifically advised for groups for which the drug has not yet been studied, such as men who've had a heart attack, stroke or life-threatening arrhythmia in the past six months, those with significant hypotension (low blood pressure) or hypertension (high blood pressure), those with unstable angina and those with retinitis pigmentosa, a disease that causes retina deterioration. The only current absolute contra-indication is the concomitant use of nitrate-containing cardiovascular medication.

Nitrates such as Glyceryl tri nitrate (GTN) or isosorbide mononitrate are usually prescribed for ischaemic heart disease and angina.

Viagra has also become popular for recreational use, for example in night-clubs. However, it is a prescription drug that should only be taken under medical supervision. Experts say that it does not have benefits for men who have normal erections. It can be lethal when used in conjunction with inhaled amyl nitrate (“poppers”), a recreational drug particularly popular among gay men. It is used to create a “rush” of sexual stimulation, but in the process also causes blood pressure to plummet to levels that may be dangerously low. This also applies to Viagra use in conjunction with heart medications that contain nitrate.

Because of the potential misuse of the drug, the Medicines Control Council, which delayed approval of the drug after reports of possible Viagra-related deaths in the US and Europe, warned that it would withdraw the drug if evidence of misuse emerged.

Viagra costs between R70 and R100 a tablet, depending on its strength. Following the phenomenal success of Viagra, several other drug companies launched similar type of drugs. Two such therapies are Vardenafil (Levitra) and Tadalafil (Cialis).

Vardenafil (Levitra)
Vardenafil or Levitra, like Viagra, is a phosphodiesterase type-5 inhibitor and was developed specifically for erectile dysfunction as an oral agent. Multiple trials have shown that Levitra (Bayer Pharmaceuticals) is effective in improving the rate of achieving and maintaining an erection during sexual intercourse. Improvement also was noted in other aspects of sexual function, including confidence, orgasmic function and overall satisfaction.

Vardenafil produces significant improvements in erectile dysfunction regardless of age, baseline severity and cause of erectile dysfunction. It is also sometimes effective in patients with diabetes and after radical prostatectomy surgery for prostate cancer. Levitra has a rapid onset of action and sexual intercourse is possible as early as 16 minutes after swallowing it.

Levitra is well tolerated with side effects very similar to that of Viagra. The most common side effects are headache, flushing, rhinitis (stuffy nose) and indigestion (heartburn), which are mild or moderate and generally decrease with continued treatment.

Levitra comes in two dosages namely ten and twenty milligrams. Ten milligrams is more than adequate for mild to moderate erectile dysfunction.

Tadalafil (Cialis)
Cialis is one of the newer PDE-5 inhibitors for the treatment of erectile dysfunction – it’s also dubbed the weekend drug for its long duration – up to 36 hours in some patients. This is because the chemical structure is different to the other two PDE-5 inhibitors. It has been demonstrated to be effective for most causes of erectile dysfunction.

Side effects, although similar to the other two PDE-5 inhibitors, have the addition of back pain that appear to be self limiting, mild and benign. Cialis is also contra-indicated with nitroglycerine or any nitrate medications because of a drop in blood pressure.

The daily use of low concentration (5mg) of Tadalafil is now available. Although expensive (R700) it might be advantageous for use after radical prostatectomy to regain erectile function.

This generic form of Viagra has recently been launched in South Africa.  It has a very similar drug profile, efficacy and dosing options and is cheaper that the others.

Other generics are coming onto the market.

It should be noted that all 3 companies manufacturing Viagra, Levitra and Cialis published a disclaimer in 2008.  They stated that several cases of sudden hearing loss were reported with these drugs.  It does not appear to be a major problem, however.

More on medication
  • Some drugs are claimed to be effective, but have not been proven to be so in scientific studies. These include yohimbine hydrochloride, dopamine and serotonin agonists, as well as trazodone.
  • Medications may be used in conjunction with counselling, psychotherapy or psychiatric medication if erectile problems have psychological causes.

Vacuum erection apparatus
This is a vacuum pump that sucks blood into the penis and then a constriction band is placed around the base to prevent outflow of blood. Intercourse can then take place. This is often a difficult process to get use to, but some men are extremely happy with it. It is safe, provided the constriction band is not left on for longer than 60 minutes.

Injection therapy
Intracavernosal injections (into the body of the penis) sounds painful, but are actually not. It will produce an erection for 20-30 minutes or longer. Different drugs can be used, namely Prostaglandin, Paraverine or Fentolamine. Prostaglandin is the most widely used and marketed as Caverject. Combination injection therapy is available at clinics and some pharmacies. Penile injections can be dangerous if incorrectly administered. The technique and dosing must be supervised by a properly trained professional.  Complications include bleeding, bruising, infection and a prolonged painful erection (priapism), which can permanently damage the penis.

Surgical treatment
Surgery for erection problems is chosen when non-surgical treatments and psychotherapy have not been effective. Surgical approaches include penile implants, which can be very successful and produce satisfactory results in 80 to 90% of men, and repairs to the vascular system in the penis – as well as surgery to correct penile curvature (Peyronie’s disease, which is a painful condition of the penis which results in deformity or curvature of the penile shaft, making penetration impossible).

  • A bendable rod can be implanted into the penis. This makes the penis rigid enough to have sex, yet leaves it flexible enough to be tucked away in your pants unobtrusively.
  • A cylinder may be implanted that extends when fluid from a reservoir tucked under the abdominal muscle is pumped into it.

This is done by manually squeezing a small pump that is connected to the reservoir and implanted into the scrotum. While implants mean that you can avoid using drugs, they do require surgery and involve all the risks normally related to surgery: adverse reaction to anaesthesia, possible blood loss and infection. About 4% of implants have had to be removed as a result of infection. In five to 10% of cases there may be mechanical failure of the device, in which case a second operation is necessary for repair or removal. Urologists perform most penile implants and costs can range from about R20 000 to more than R60 000, depending on the type of implant.

Surgery to repair or remove blood vessels of the penis may be appropriate in the case of a young man who suffers erectile dysfunction as a result of injury, such as a car accident. In older men, it tends to be more difficult to repair damaged blood vessels, as damage may be extensive. These specialised blood vessel repair (revascularisation) operations should only be done by specially trained urologic surgeons.

Venous occlusion:
Reduction of venous outflow can sometimes improve erections. This condition is very rare and the operation will only be performed after proper workup using blood flow evaluations.


Many erection problems can be prevented or even reversed by a more relaxed approach to sex and by rediscovering sensuality. Sexual intimacy is a form of communication. If you and your partner talk about your lovemaking, it will help reduce your stress and anxiety so that your sexual activity may become more relaxed. Many people avoid talking about problems in their sexual relationship.

It may gradually become more difficult to get and maintain an erection as you get older. However, foreplay and the right environment can increase your ability to have an erection, regardless of your age. Add to this: a healthy lifestyle, maintaining the correct weight, doing exercise, not smoking and treating underlying diseases.  What is good for your heart is good for your penis.

Bicycle seats and impotence
Cycling is an important exercise to keep fit. In a small percentage of men it might cause erectile dysfunction which is usually temporary. Special saddles might lower the risk. In fact, studies have shown that cyclists in general have a lower rate of erectile dysfunction than the general population – probably because of their improved cardiovascular health.

- (Reviewed by Dr Stephen Mark Eppel, Urologist, Christiaan Barnard Memorial Hospital, Cape Town. MBBCh (Wits), FRCS (Edin), American Board of Urology (ABU), November 2013)


Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.

Ask the Expert

Erectile Dysfunction Expert

Dr Kenny du Toit is a urologist practicing in Rondebosch, Cape Town. He is also consultant at Tygerberg hospital, where he is a senior lecturer at Stellenbosch University. He is a member of the South African Urological Association, Colleges of Medicine South Africa and Société Internationale d’Urologie. Board registered with both the HPCSA (Health professions council of South Africa) and GMC (General medical council UK). He has a keen interest in oncology, kidney stones and erectile dysfunction.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules