Impotence causes

Impotence, also known as erectile dysfunction or ED, is a condition in which a man is unable to get or hold an erection long enough to have a satisfactory sex life. Impotence is a common problem, affecting up to half of Australian men between the ages of 40 and 70 years. The risk of developing erectile dysfunction increases as you get older.

In the past, doctors considered impotence to be a mainly psychological problem, caused by performance anxiety or stress. Now, doctors know that many cases of impotence have a physical cause, which usually can be treated. Often, a combination of physical and psychological factors contributes to erectile dysfunction.

Physical causes of impotence

Physical causes of impotence can include:

  • problems with blood to flow into and out of the penis;
  • damage to the nerves that send signals from the body’s central nervous system to the penis; and, more rarely,
  • a deficiency in testosterone or other hormones.

Some medicines can contribute to impotence, as can some types of surgery and radiotherapy treatments.

Blocked blood vessels to the penis

A very common cause of impotence is when blood flow into the penis is reduced. This can be due to atherosclerosis, also known as hardening of the arteries. In atherosclerosis, the arteries are clogged and narrowed, resulting in reduced blood flow.

Risk factors for atherosclerosis include:

  • high cholesterol;
  • high blood pressure;
  • obesity;
  • sleep apnoea;
  • diabetes; and
  • smoking.

If your erection problems are caused by atherosclerosis, there is a chance that the arteries in other parts of your body (e.g. the coronary arteries that supply your heart) are also affected by atherosclerosis. In fact, erection problems may be the first sign that you are at risk of coronary heart disease.

Because the arteries to the penis are narrower than those to the heart, you may develop symptoms of erectile dysfunction before you experience any symptoms of heart disease, such as angina. So seeing your doctor about erection problems may be important for your overall physical health.

Impotence can also be caused by a blood clot that prevents enough blood from flowing into the penis to cause an erection.

Venous leakage

In some men, blood can flow in to the penis easily, but the problem is that it leaks out again, so an erection cannot be sustained. This is called venous leakage. Doctors aren’t certain of the cause of venous leakage, but they can perform surgery to help repair it.

Medicines that can cause impotence

Many medicines can cause erection problems as a side effect, including:

  • diuretics (sometimes known as ‘water tablets’ - often used for high blood pressure);
  • high blood pressure medications;
  • cholesterol-lowering medicines (including statins);
  • some types of antipsychotics;
  • antidepressants;
  • cancer treatments;
  • some medicines used to treat heartburn and stomach ulcers;
  • antihistamines;
  • some pain medicines; and
  • certain epilepsy medications.

If you experience impotence after starting a new medication, tell your doctor, who may be able to prescribe a different medicine for you. Don’t stop taking a medicine without first consulting your doctor. You should also tell your doctor about any over-the-counter medicines or complementary remedies you may be taking.

The following table contains a list of specific medicines that may cause or contribute to erectile dysfunction. This list may not cover all types of medicines that can cause erectile dysfunction, so always ask your doctor if you are in doubt. Also, for some of these medicines ED is a very rare side effect. Most men taking these medicines do not experience erectile dysfunction.

Medicines that may cause erectile dysfunction
Type of medicineExamples
ACE inhibitorscaptopril (Capoten), enalapril (Renitec), perindopril (Perindo), ramipril (Tritace), and others
Antidepressantsamitriptyline (Endep), clomipramine (Anafranil), desvenlafaxine (Pristiq), fluoxetine (Prozac), paroxetine (Aropax), sertraline (Zoloft), venlafaxine (Altven, Efexor), and others
Anti-epilepticsclonazepam (Rivotril), pregabalin (Lyrica)
Antifungalsitraconazole (Sporanox)
Anti-ulcer drugscimetidine (Magicul), nizatidine (Tazac), ranitidine (Zantac), and others
Beta-blockerspropranolol (Inderal), metoprolol (Betaloc, Lopresor), and others
Other blood pressure-lowering medicinesclonidine (Catapres), lercanidipine/enalapril (Zan-Extra), losartan (Cozaar), perindopril/amlodipine (Coveram), olmesartan/amlodipine (Sevikar), telmisartan/amlodipine (Twynsta), valsartan/hydrochlorothiazide (Co-Diovan)
Calcium-channel blockersdiltiazem (Cardizem), felodipine (Plendil), nifedipine (Adalat)
Cholesterol-lowering drugsatorvastatin (Lipitor), ezetimibe/simvastatin (Vytorin), fluvastatin (Lescol, Vastin), gemfibrozil (Ausgem), pravastatin (Pravachol), simvastatin (APO-simvastatin, Lipex, Zocor), and others
Diuretics ('water tablets')bumetanide (Burinex), chlorthalidone (Hygroton), spironolactone (Aldactone), and others
Schizophrenia drugsamisulpride (Solian, Sulprix), haloperidol (Haldol, Serenace), olanzapine (Lanzek, Ozin, Zypine, Zyprexa), paliperidone (Invega), risperidone (Rispa, Risperdal), ziprasidone (Zeldox)
Combination cholesterol-lowering and anti-hypertensiveamlodipine/atorvastatin (Caduet, Cadatin)
Pain medicinesfentanyl (Denpax, Durogesic), hydromorphone (Jurnista), morphine (Momex SR, MS Contin), oxycodone (OxyContin, OxyNorm, Targin), tramadol
Miscellaneousoestrogens, antiandrogens, anticancer drugs and some chemotherapy treatments, baclofen (Clofen, Lioresal); cyproterone (Androcur, Cyprohexal, Cyprostat), degarelix (Firmagon), etoricoxib (Arcoxia), finasteride (Proscar and Propecia), flutamide (Flutamin), rotigotine (Neupro), triptorelin (Diphereline)

*The names in brackets are just some examples of the trade names each specific medicine is marketed under in Australia. The medicine may also be known by other trade names.

Diabetes and erectile dysfunction

Men who have diabetes have a higher risk of developing impotence than other men. Diabetes contributes to impotence because it can damage blood vessels and cause a type of nerve damage known as peripheral neuropathy.

Hormones and impotence

Low levels of the male hormone, testosterone, are more commonly linked to a lowered sex drive, rather than impotence itself. Only a small percentage of cases of impotence are caused by hormone deficiency.

Low testosterone levels may be the result of a condition called hypogonadism, in which the testicles don’t produce enough testosterone. More rarely, low testosterone can be caused by the pituitary (a small gland at the base of the brain) not secreting sufficient hormones to stimulate the testes to produce testosterone. The pituitary is also sometimes affected by small benign (non-cancerous) tumours that secrete prolactin, another hormone that can cause impotence.

Mildly decreased levels of testosterone are often not due to specific testicular or pituitary problems, but rather stress or depression. In this situation, testosterone replacement is rarely of any benefit.

Other hormone problems, including thyroid disease, can also cause impotence.

Prostate cancer and erectile dysfunction

The advanced stages of prostate cancer can affect the nerves and arteries that are vital for an erection.

Radiation treatment for prostate cancer can harm the erectile tissues of the penis, and prostate cancer surgery can cause nerve or artery damage to the penis.

Treatment for advanced prostate cancer often includes medicines that counteract testosterone, and commonly cause erectile dysfunction as well as loss of sexual interest.

Peyronie’s disease

Peyronie’s disease is an uncommon condition that affects a man’s sex life because his penis curves abnormally and causes pain when he has an erection. He might also be unable to have a hard erection. The curvature of the penis is caused by a scar, called a plaque, that forms in the penis.

Other physical causes of impotence

Several other factors and conditions can contribute to erectile dysfunction, including the following.

  • Depression. Many men find that when they’re suffering from depression, they lose interest in sex and can’t get or keep an erection. Asking your doctor for treatments for depression may help alleviate your erection problems as well.
  • Smoking contributes to vascular disease (disease of the blood vessels), so it can contribute to erectile dysfunction by affecting blood flow to the penis. Giving up smoking often has a beneficial effect on erectile function.
  • Excessive alcohol use. Alcoholism can cause permanent nerve damage, resulting in impotence. This nerve damage is called peripheral neuropathy. Long-term alcohol use can impair the liver’s ability to function, resulting in a hormone imbalance in which a man has too much of the female sex hormone, oestrogen. On a day-to-day level, alcohol dulls the central nervous system, adversely affecting sexual response.
  • Illicit drug use. Illicit drugs such as marijuana, cocaine, heroin, barbiturates, and amphetamines act on the central nervous system, impairing the body’s ability to respond sexually.
  • Certain exercises. Nerve and artery damage can be caused by prolonged cycling, rodeo riding, or use of a rowing machine, resulting in the inability to get an erection. Often, minimising the use of hard bicycle seats and exercise machine seats, as well as correct positioning of the seat, will help restore sexual function.
  • Surgery to organs near the nerve pathways of the penis, such as the bladder, rectum and prostate, can cause nerve or artery damage to the penis, resulting in the inability to have an erection.
  • Injuries. Impotence can be caused by spinal cord injury; injury to your sex organs; or a pelvic fracture, which can cause damage to the nerves of the penis, or damage the blood vessels, resulting in reduced blood flow to the penis.
  • Conditions affecting the nervous system. Multiple sclerosis (MS) and other degenerative diseases of the nervous system, such as Parkinson’s disease, can damage the nerves involved in erections.

Psychological causes of impotence

Most cases of impotence have physical causes, but, in some men, psychological factors are the main contributors to impotence.

Impotence that’s triggered by psychological factors is more common in men who are sexually inexperienced. Psychological erectile dysfunction may only occur when you’re with just one particular person. You’re also more likely to have morning erections, and be able to have an erection when you masturbate, than men whose impotence has a physical cause.

Here are some psychological factors that can have an impact on your erections.

Stress and anxiety

When you’re stressed and focusing on other issues apart from sex, you might find that you don’t want to have sex as often and there might be a drop in your ability to perform when you do try. You might find that tackling the source of your stress can have benefits in the bedroom as well.

Fear of failure

Anxiety about your sexual prowess (commonly called performance anxiety) can, in itself, contribute to failure. By putting pressure on yourself, you become too anxious to get an adequate erection.

Most men experience isolated episodes of erectile failure. Even when the transient physical cause has passed, anxiety that it may recur is sufficient to prevent erection. Anxiety, whether about something specifically sexual or part of a wider anxiety syndrome, is never helpful to good sexual function.

Problems with your relationship and impotence

Impotence may be a manifestation of a poor relationship, or a problematic time in a relationship. Sexual boredom, tension or anger among partners, and lack of intimacy and communication are all possible triggers of erectile dysfunction. In these cases, seeing a counsellor may help.

It’s worth remembering that impotence is a complex medical condition, which may have more than one cause. For example, if impotence is the result of a side effect of medicine or an underlying disease, the anxiety caused by lack of performance may perpetuate the erectile dysfunction even after the physical cause has been dealt with.

Almost any chronic (ongoing) physical or mental health disorder, including those with no direct effect on penile nerves or blood supply, can have a powerful effect on sexuality, sexual self-image and erectile function.

If you’re worried about your sexual response or the quality of your erections, don’t be afraid to talk to your doctor, who has access to treatments that can help.

Last Reviewed: 16 December 2016
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References

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2. Andrology Australia. Erectile dysfunction (updated May 2014). https://www.andrologyaustralia.org/wp-content/uploads/Factsheet_ErectileDysfunction.pdf (accessed Nov 2016).
3. Mayo Clinic. Erectile dysfunction (updated 25 May 2016). http://www.mayoclinic.org/diseases-conditions/erectile-dysfunction/basics/definition/con-20034244 (accessed Nov 2016).
4. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Erectile dysfunction (updated Nov 2015). https://www.niddk.nih.gov/health-information/health-topics/urologic-disease/erectile-dysfunction/Pages/facts.aspx (accessed Nov 2016).
5. Medline Plus. US National Library of Medicine. NIH National Institutes of Health. Drugs that may cause impotence (updated 21 Jan 2015). http://www.nlm.nih.gov/medlineplus/ency/article/004024.htm (accessed Nov 2016).
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