Erectile dysfunction

Also known as impotence

Erectile dysfunction means a man is unable to maintain an erect penis sufficient for satisfactory sexual intercourse. Many men have erection problems at times, and the likelihood increases with age.

Erectile dysfunction is not a disease, but a symptom of some other problem, either physical or psychological or a mixture of both. It is distressing and may cause loss of confidence and self-esteem or depression, as well as relationship problems. There are several solutions, but recognising the problem and talking about it with your doctor are the first essential steps.

How does an erection happen?

Getting an erection is a complicated process. The veins that allow blood to leave the penis are only so wide. During an erection, the blood vessels that let blood into the penis relax and widen (dilate). This lets more blood in which causes the sponge-like tissues of the penis to swell and harden.

Your thoughts and senses (touch, hearing, smell and sight) influence a part of the brain that can trigger an erection.

In addition, hormones and other substances determine how your nerves transmit ‘sexual signals’ and how blood vessels respond to the received signals. Arousing thoughts or nervous mechanisms such as  touch reflexes are two ways an erection is initiated.

What causes an erection to fail?

Erectile dysfunction occurs when sexual stimulation or arousal (you may still ‘have the urge’) does not result in sufficient blood flow to the penis. For most men there is a physical or medical reason for this, for others the problem is related to thoughts or emotions.

Even when there is an initial physical reason, a man may still feel anxious about having sex, and this can compound the problem.

Alcohol, smoking and recreational drugs

Smoking, drinking alcohol and the use of recreational drugs such as narcotics, stimulants and hallucinogens also affect sexual function. Chemicals from smoking can interfere with blood flow to the penis and can damage the lining of blood vessels or lead to atherosclerosis (hardening of the arteries). It can also affect the smooth muscle tissue that needs to relax to allow blood to flow in. Short-term use of alcohol affects sexual desire and diminishes performance and delays orgasm and ejaculation.

Medical reasons

Medical  cause  Description
Hormone imbalance A deficiency of male hormones can reduce your desire or interest in sexual function such as thyroid disease, acromegaly, hypogonadism
Nerve damage This can result in reduced sensitivity, or reduced signals to your penis to release the chemicals that cause erection. Examples of nerve damage include spinal cord injury, multiple sclerosis and Parkinson’s disease. Pelvic surgery including some cancer operations on the prostate, bladder or bowel may result in nerve damage leading to erectile dysfunction.
Disease of the blood vessels Blood vessels often become narrowed and hardened with increasing age. This reduces blood supply to your penis. Examples of diseases that affect blood vessels include diabetes, hypertension and high cholesterol.

Medicines that can cause erectile dysfunction

Some medicines including over-the-counter (OTC) medicines can cause sexual problems including getting and maintaining an erection. This may vary depending on the individual and type of medication. Examples of medicines that are known to cause sexual problems in some people are:

  • antidepressants
  • antipsychotics
  • cardiovascular medicines
  • anti-epileptic medicines
  • treatments for cancer
  • medicines for bladder and prostate problems
  • corticosteroids.

If you are taking a medicine and are worried about its effects — do not stop taking your medicine suddenly. Rather, discuss this with your doctor or pharmacist. Sometimes there might be a different medicine that you can take that is less likely to cause sexual problems. Read more about medicines and sexual problems.

Psychological reasons

There are a range of psychological factors including:

  • existing values or attitudes towards sex
  • stress, guilt, depression or fatigue
  • anxiety about your performance during sex
  • relationship problems (possible anger, power or control issues with your partner)
  • problems with intimacy and communication.

If you still have erections at times (eg, when you wake) this usually means psychological reasons are involved.

What are the symptoms of erectile dysfunction?

Some estimates indicate that about 40% of men over the age of 40 will have erection problems at times. Symptoms of erection problems include:

  • being unable to get an erection
  • experiencing a partial erection
  • having an erection of a shorter than usual duration.

How is erectile dysfunction diagnosed?

Many men are unhappy with their ability to get or maintain an erection, but only 5% of these men seek help. This is because most men, in general, are unwilling to discuss their sex life, even when it is going well.

Understanding that erectile dysfunction could have a medical cause, just as asthma or arthritis do, can allow you to feel more at ease in mentioning it to your doctor. By opening up this discussion, which is confidential, your doctor can help you in a number of ways.

Your doctor can check your health and any current medications for likely side effects. If psychological reasons are suspected, your doctor can advise you on the appropriate action and help you access counselling services you (and your partner) may benefit from.

Tests by your doctor may include:

  • A physical examination, which may include the genitals and prostate gland.
  • Checking your medications for side effects.
  • Blood and urine tests for hormones, blood lipids, liver and kidney function and diabetes.

If your erection problems have a medical cause, your doctor can explain the treatment options, the techniques needed to make them work and their suitability for your needs in the light of your overall health.

How is erectile dysfunction treated?

The available treatments for erectile dysfunction are summarised below. Your doctor can advise you on the benefits and drawbacks of each. 

  • psychological counselling (whether or not there is a medical cause)
  • oral tablets
  • self-injection or penile insertion of a drug
  • vacuum pump devices
  • rigid or inflatable surgical penile implants
  • testosterone replacement (only for men with low levels of this hormone).


Tablets for erectile dysfunction are called phosphodiesterase-5 (PDE5) inhibitors such as sildenafil (Viagra, Silvasta), tadalafil (Cialis) and vardenafil (Levitra). These medicines usually enable an erection by relaxing the blood vessels in the penis, but only when the man is stimulated or aroused.

  • They work well for most men with erectile dysfunction, allowing intercourse (or sex) in about 70% (7 out of every 10) users, but may work as well for men with diabetes and who have had prostate surgery, or severe erectile dysfunction.
  • While all the medications essentially work the same, some must be taken 20-30 minutes before intercourse and are for that one time use. There are also low-dose medications that can be taken daily.
  • PDE5 inhibitors are not suitable for everyone. They may not be safe in you have certain medical conditions and are taking some medications such as nitrates.
  • Talk to your doctor about which treatment is right for you as this will depend on the possible causes. If there are no health concerns, you can buy sildenafil directly from some pharmacies after a consultation with the pharmacist or see a doctor for a prescription. 

Talk to your doctor about which treatment is right for you as this will depend on the possible causes. If there are no health concerns, you can buy sildenafil directly from some pharmacies after a consultation with the pharmacist or see a doctor for a prescription. Read more about sildenafil (Viagra, Silvasta), tadalafil (Cialis) and vardenafil (Levitra).


If the tablets mentioned above don't work, then injecting a medicine called Caverject, into the base of the penis is another option. It allows most men to get an erection, which may last beyond ejaculation. Some men may be put off by this method, but the injector devices are simple and convenient to use and the procedure is virtually painless.

Do herbal products work?

Many herbal products such as Horny goat weed, ginkgo, yohimbe and ginseng claim to improve sexual function. There is no sound evidence that these herbal products work well for erectile dysfunction. They have not been well-studied or tested. Since some erectile dysfunction is related to psychological problems, herbal products may help with anxiety, which may indirectly help sexual function. Some herbal products and supplements can cause side effects or interact with other medicines. Talk to your doctor or pharmacist before you try an alternative treatment for erectile dysfunction — especially if you're taking medications or you have a chronic health problem such as heart disease or diabetes.      

Self-care for erectile dysfunction

Most ageing men manage to get erections, but to do so requires more stimulation. It is up to each man to decide whether his erection is adequate. You can consider (with your partner) how important sexual intercourse is to your relationship – there are other aspects to intimacy, and not all couples require an active sex life to have a fulfilling relationship.

You can help yourself by cutting down on alcoholstopping smoking and reducing the stress in your life.


  1. Erectile dysfunction Best Practice Journal, April 2008
  2. Erectile Problems Best Health (UK), 2014
  3. Dietary supplements for erectile dysfunction: A natural treatment for ED?  Mayo Clinic (US), 2017 
Credits: Health Navigator Editorial Team. Last reviewed: 12 Nov 2018