Erectile dysfunction

Also known as impotence

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

Key points

  1. Erectile dysfunction is not a disease, but a symptom of some other problem, either physical or psychological or a mixture of both.
  2. It can be distressing and may cause loss of confidence and self-esteem or depression, as well as relationship problems.
  3. There are several solutions, but recognising the problem and talking about it with your doctor are the key first steps.
  4. You can help yourself by cutting down on alcoholstopping smoking  and reducing the stress in your life.

How does an erection happen?

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

Your thoughts and senses (touch, hearing, smell and sight) influence a part of your 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 you can get an erection.

What causes an erection to fail?

Erectile dysfunction occurs when sexual stimulation or arousal does not result in enough blood flow to your penis, even though you may still have the urge. 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, when this has passed you may still feel anxious about having sex and this can add to 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 your 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 reduces 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. This may be caused by thyroid disease, acromegaly or hypogonadism.
Nerve damage This can lead to reduced sensitivity or reduced signals to your penis to release the chemicals that cause erection. Nerve damage can be caused by spinal cord injury, multiple sclerosis and Parkinson’s disease. Pelvic surgery including some cancer operations on your prostate, bladder or bowel may result in nerve damage leading to erectile dysfunction.
Blood vessel disease Blood vessels often become narrowed and hardened with increasing age. This reduces blood supply to your penis. Diseases that affect blood vessels include diabetes, hypertension and high cholesterol.

Medicines that can cause erectile dysfunction

Some medicines, including over-the-counter medicines, can cause sexual problems, including getting and maintaining an erection. This may vary depending on the person and type of medication. Medicines 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, don't stop taking it suddenly. Rather, discuss this with your doctor or pharmacist. There might be a different medicine 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 affecting erection 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 help you to feel more at ease in mentioning it to your doctor. Your doctor is used to talking about these issues. By opening up this discussion, which is confidential, your doctor can help you in a number of ways.

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

Tests by your doctor may include:

  • a physical examination, which may include your 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 based on your overall health.

How is erectile dysfunction treated?

There are several treatments for erectile dysfunction. Your doctor can advise you on the benefits and drawbacks of each. 

Psychological counselling 

This can be useful even if there is a medical cause, as it gives you a chance to talk about how you feel about having erectile dysfunction. If there is an underlying psychological reason for the difficulty, this is a safe place to explore what this might be and what you can do about it. 

Oral tablets

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 your penis, but only when you are 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. They may also work for men with diabetes and who have had prostate surgery, or who have 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 if 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. 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 your 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.

Other possible treatments

For some men, vacuum pump devices, rigid or inflatable surgical penile implants or testosterone replacement (only for men with low levels of this hormone) may also be options. Discuss these with your doctor.

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 BPAC, NZ, 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.