Erectile dysfunction


Erectile dysfunction is the inability to achieve a satisfactory erection for sexual intercourse. This problem can affect men of all ages, but is more common in older men.

Image by Sander van der Wel


During sexual stimulation, the small arteries of the penis open up and bring more blood to the erectile tissue.  As the erectile tissue expands, it compresses and closes up the veins which return the blood back to the body. Thus, blood is trapped in the erectile tissue and this causes the erection.

Erectile dysfunction can be caused by one or more of the following:

  • Medical illnesses that damage the small arteries of the penis, eg. diabetes mellitus, high cholesterol
  • Stiffness of the erectile tissue which leads to inadequate closure of the veins. This can be due to old age or previous injury to the penis
  • Damage to the nerves that control erection eg. pelvic surgery, spinal cord injury
  • Abnormalities in  hormone levels eg. Low testosterone, high levels of prolactin
  • Psychological causes eg. anxiety, stressful events

Should I see a doctor?
Yes you should seek medical advice. Erectile dysfunction can be the first sign of a serious illness such as diabetes mellitus.


The common medications for erectile dysfunction are sildenafil (Viagra), tadalafil (Cialis) and Vardenafil (Levitra). They are usually taken as needed before intercourse. Low dose Cialis can be taken on a daily basis. If oral medications do not work, the patient may opt to self-administer injections to the penis as needed before intercourse.

Surgery is sometimes required for treatment of erectile dysfunction. The most common surgery is a penile implant, where a permanent inflatable device is implanted into the penis for use during intercourse. This procedure has a good outcome but 5 to 10% of patients will experience mechanical failure of the device and require a reoperation.

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