Your Health A-Z

Erectile dysfunction (impotence)

Erectile dysfunction is the inability to get or maintain an erection that is sufficient to ensure satisfactory sex for both partners. Learn more about this condition.
  • 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 primarily physical.
  • Most men experience occasional problems with obtaining an adequate erection, and this should not be a cause for concern.
  • Erectile dysfunction can be treated at any age.
  • Treatment options include psychotherapy, drug therapy, vacuum pumps and surgery.


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 such as Levitra, 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.


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 can be grouped into two general types: physical (related to the blood vessels and/or nerves) and psychological. 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 causes are physical in 85 to 90% of cases.

The events that lead to a successful erection

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 out. 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, 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.
  • Complications of surgery or radiation (eg 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.
  • Zinc deficiency.
  • Erection problems in men over 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 that caused by major life changes
  • Grief and other reactions to major loss: recently widowed men may have erection problems.
  • Low self-esteem
  • Erection problems in men under 50 are more likely to be due to psychological causes.


Symptoms of erectile dysfunction:

  • Inability to have an erection at any time, either alone or with a sexual

  • Inability to maintain an adequate erection until completion of the sexual

If impotence:

  • Is only temporary or occasional, the problem is probably not serious; all
    men go through periods of erection 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.


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 five percent of men at the age of 40 and between 15 and 25% of men at the age of 65 suffer from erectile dysfunction and the percentage grows to 70% as men reach 80 years of age. 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.


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

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 leads to low levels of testosterone, the hormone necessary for erections, but does not affect the nerves or blood vessels. Thyroid problems may also increase the risk of erection problems.
  • Multiple sclerosis
  • 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)

When to see a doctor

See a health professional if erection problems occur with:

  • Any type of injury to the back, legs, buttocks, groin, penis, or testicles
  • A loss of pubic or armpit hair and breast enlargement

See a health professional within a week or two if erection problems occur more than 25% of the time and the problem:

  • Occurs with a persistent backache
  • Occurs after you start taking a new medication or change your dosage
  • Affects your self-image or sense of well-being
  • Has not improved despite self-care

Watch and wait if you've 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 specialised in this area, and your GP will be able to refer you to one.


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

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

  • History taking. He may ask about your sex life, diseases you've had and drugs prescribed to you. This will enable him to review risk factors.
  • A complete physical exam (including the abdomen, penis, prostate, rectum, and testicles). If the penis does not respond as expected to certain touch stimuli, there may be a problem with the nervous system. 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 creatinine (a waste product of protein metabolism). 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. 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. The modern era of effective oral treatment has reduced the indications for penile tumescence testing drastically.
  • Tests to evaluate the 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).
  • Extensive nervous system tests. These are not well 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 medications, other non-surgical treatments or surgery.



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:

  • Oral medication.
  • Medication you can inject or insert into the penis to get an erection.
  • Alteration of existing medication for other conditions.
  • Vacuum devices.
  • Penile implants.
  • Psychotherapy or behavioural therapy – even when the erection problem has physical causes.

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.

Home treatment

If you only experience occasional episodes of erectile dysfunction, you may be able to treat it at home without a doctor's help.

  • Some of the causes of erection failure are within your control, such as stress, smoking, and alcohol use.
  • Talk to your partner. Often sharing your worries about sexual performance with your partner can break a vicious cycle of anxiety. You may find out that your partner does not view the problem as seriously as you do. This may leave you freer to enjoy sexual activity instead of consciously tracking your performance.
  • Make some time together to enjoy simple sensual pleasure, such as caressing and massaging without the goal of having sexual intercourse or even an erection. You may discover new kinds of sexual pleasure while you reserve intercourse for another occasion when you are more at ease.
  • Sexual problems are often the result of underlying difficult feelings between you and your partner. Are you angry with him or her? Are you worried about rejection? Talk openly about these feelings and try to resolve conflicts. At the same time you might want to reassure your partner that erectile dysfunction very seldom arises from lack of sexual interest.
  • Pelvic-floor exercises (similar to Kegel exercises) may be helpful in some men with erection problems. These exercises have no risks.
  • Don't be embarrassed about seeking professional help if home strategies don't help and erection problems are persistent and troublesome.


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

Drug therapy can have various goals:

    • Impotence (erectile dysfunction) 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 primarily physical.
    • Most men experience occasional problems with obtaining an adequate erection, and this should not be a cause for concern.
    • Erectile dysfunction can be treated at any age.
    • Treatment options include psychotherapy, drug therapy, vacuum pumps and surgery.
  • 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.
Vardenafil (Levitra), tadalafil (Cialis) and sildenafil (Viagra)

These prescription drugs, called phosphodiesterase type 5 (PDE-5) inhibitors, are regarded as the first-line treatment for most cases of erectile dysfunction. The medication is taken orally and helps men to get and keep an erection with sexual stimulation. They cannot help men to have an erection if they are not sexually stimulated.

One of the benefits of this form of treatment is that it is taken before sexual intercourse and therefore doesn't interrupt the sex act. The amount of time before a couple is ready for sexual intercourse when taking these tablets varies according to which medication is prescribed.


Alprostadil (al-PROS-tuh-dil) is a synthetic form of the hormone prostaglandin E. This hormone helps relax smooth muscle tissue in the penis, which in turn allows blood to flow into the cylinders of sponge tissue, causing an erection. There are two ways to deliver the drug to the penis:

1. Injection into the penis (Caverjet)
The idea might make you flinch, but it's not as scary or painful as it might sound. You use a very fine needle, which minimises pain, to inject the drug into the base or side of the penis five to 20 minutes before you want to start sexual activity. Once you've had some practice to get the technique and dose right, it's easy. The erection lasts between 30 and 60 minutes. This medication (sold under the trade name of Caverjet) should not be used more than three times a week. As with any medication, there is some risk: repeated injections may cause internal scarring that can worsen impotence in about five percent of men. Another possible complication is that of an erection that does not abate for longer than four hours (priapism). Far from turning you into a sexual long-distance athlete, this condition can damage the penis permanently if it does not receive prompt medical attention. Fortunately, only about one percent of men who regularly use injections will experience this problem. Another possible side-effect is minor bleeding from the injection site.

Regular use of Caverjet can be difficult to afford at a cost of about R110 per use.

2. Muse
The Medicated Urethral System for Erection (Muse) uses a disposable applicator to squirt a pre-measured dose of alprostadil, about the size of half a grain of rice, into the opening at the tip of the penis. It may cause a little discomfort or pain. The technique is successful for about 60% of men. In addition to the medication, you may need to fit a rubber band around the base of your penis to help prevent blood draining out and loss of the erection. Side effects may include a little bleeding and scar tissue formation. The cost of Muse varies, depending on strength, between about R110 and R124 per use.

Apomorphine SL (Uprima)

Unlike Viagra which works directly on the penis, apomorphine has a central effect in the brain. Apomorphine stimulates dopamine receptors in an area of the brain that is important in the initiation of erection. This causes a cascade of events that eventually leads to an erection. Apomorphine SL has recently been approved for marketing in Europe at doses of 2 and 3 mg. Apomorphine is administered under the tongue and reaches its maximum effect in 15-20 minutes. The patient must drink some water before placing apomorphine under the tongue, to wet the mucosa of the throat and facilitate dissolution of the tablet (a process which takes 10 min). There is no interaction of apomorphine with food or alcohol, but the concomitant use of alcohol should be discouraged, as it is known to reduce erectile capacity.

  • 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, and trazodone.
  • Medications may be used in conjunction with counselling, psychotherapy or psychiatric medication if your erectile problems have psychological causes.


Surgery for erection problems is frequently 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.

  • 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 all the risks normally related to surgery: adverse reaction to anaesthesia, possible blood loss, and infection. About two percent of implants have 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 cost can range from about R6 000 to more than R20 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 be done by specially trained urologic surgeons.


Other treatments for erectile dysfunction include vacuum devices that produce erections, and psychotherapy, which can be very effective.

  • Vacuum devices are small pumps attached to a cylinder you fit around your penis. Air is pumped out of the cylinder to create a vacuum, and the lowered pressure increases blood flow into the penis. The blood is trapped by rolling a special rubber ring down to the base of the penis. More fashionable versions of these rings, made from metal or studded leather, can also be bought from sex shops, if it appeals to you to make the intervention less clinical in this way. The pumps are useful for all types of erection problems (physical, psychological, or a combination of both). Vacuum pumps are generally safe, simple to operate and can be used as often as desired. However, improper use can damage your penis and so they must be used under a doctor's care. While you may need to interrupt foreplay to use them, you can also incorporate use of the pump into erotic play, making it less medical and more natural.
  • Psychotherapy is recommended for men whose erection problems are due to psychological causes. It may be used in conjunction with drug treatment or vacuum devices for erection problems that have both psychological and physical causes. The psychotherapist may use techniques aimed at reducing anxiety associated with sexual intercourse. Another goal is to work on the relationship between the partners by developing greater intimacy, trust and better sexual communication. Psychotherapy often involves special sex exercises for you and your partner to do at home.


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 becomes 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.

Bicycle seats can cause impotence

If you're a cyclist, it's a good idea to lift out of your seat when you're going over bumpy terrain. This could help avoid vascular damage that may lead to erectile dysfunction. Researchers found that the typical narrow, pointed bike seat can crush the arteries that fill the penis with blood. When a male sits on a narrow bike seat, too much weight is placed on the area between the anus and the scrotum, where the cavernosal arteries are located. Researcher Pedram Salimpour of the Boston University School of Medicine found that about four percent of cyclists studied suffered impotence, compared to one percent of runners. Salimpour says the problem can be avoided by using special bike seats with oval gaps, similar to a toilet seat.

(Reviewed by Dr Pieter J. le Roux)

The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.