What causes erectile dysfunction (ED)?

Age

It is estimated that between 30-40% of men aged 40 years, have suffered from some degree of erectile dysfunction.

Vascular Disease

An alteration in vascular haemodynamics is thought to be the leading cause of organic ED. It may affect those suffering from:

  • Myocardial infarction
  • Coronary artery disease
  • Stroke
  • Peripheral vascular disease
  • Hypertension
  • Atherosclerosis/dyslipidaemia

Smoking

Smoking in itself does not cause ED, but it is a risk factor especially for those suffering from heart disease and hypertension.

Diabetes

The prevalence of ED in diabetics has shown to be consistently higher then the general population. It is also age related, with an incidence risk of 15% at 34 years increasing to a risk of 55% at 60 years.

High density lipoprotein cholesterol

The risk of suffering ED was inversely proportional to the level of HDL-C. HDL-C acts as a scavenger in the body by mopping up low density lipoproteins ("bad cholesterol") in the blood and returning it to the liver where it can be removed by the body. This means the higher the level of HDL-C the lower the incidence of ED. 

Surgery or trauma

Surgery or trauma that affects the nerves or the blood supply to the penis increases the risk of ED. Other suggested causes include crossbar injuries from cycling and fractures of the pelvis.

Drugs

It is thought that drug related ED is common, and may occur in up to 25% of patients in a medical outpatient clinic. Such drugs include thiazide diuretics, the most common cause of drug induced ED because of their common usage to treat hypertension and oedema (fluid retention). Some antihypertensive agents may affect up to 40% of patients, both by blocking calcium channels and by reducing the systemic blood pressure necessary to maintain penile rigidity. Anti-androgens such as oestrogens, H2 antagonists (suppress secretion of gastric acid) and spironolactone may also cause ED. Antidepressants may also be a cause by way of affecting central nervous system mechanisms. Digoxin inhibits the Na+/K+-ATPase pump, leading to an increase in intracellular calcium that causes an increase in tone of corporal smooth muscle.

Psychological state

Erectile dysfunction has a positive correlation with depression, indices of anger, anxiety, stress, tiredness and familiarity or dissatisfaction with a relationship. Dominant personality traits have shown to have a negative correlation with ED.

Any condition that leads to a diminished sexual interest can cause ED.

Hypogonadism

Men suffering from hypogonadism, whether it be primary or secondary, characteristically suffer from a lack of sexual desire and a decrease in both frequency and intensity in response to sexual stimuli,

Erectile dysfunction also affects those who have experienced any of the following:

  • Prolactinoma
  • Adult castration
  • Alcoholism
  • Acromegaly
  • Chronic renal failure