Erectile dysfunction (ED) is trouble getting or keeping an erection of the penis that is firm enough for sex.


An erection happens when blood fills the penis. Some blood vessels opens wide to let blood flow into the penis. Other blood vessels shrink to keep the blood from leaving the penis. The change in the blood vessels is controlled by signals from nerves. ED may be caused by problems with any of these steps, such as:

Venous Leak

The blood vessels that keep the blood in the penis may be injured or have disease. Blood can leak out from the damaged areas during an erection. It may be difficult to get or keep an erection because the blood keeps leaking out.

Neurovascular Function

ED may be caused by:

  • Damage to nerves that control blood vessels
  • Damage to nerves that affect feeling in the penis
  • Damage or disease in blood vessels of the penis

Blood Vessels and Nerves of the Male Pelvis
Nerves, blood vessels, penis
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Psychological Factors

Emotional stress may change nerve signals from the brain. This is more likely a cause in men who suddenly develop ED.

Risk Factors

ED is more common in men who are 65 and older. It is also more common in men of Hispanic descent.

Factors that increase your chance of developing ED include:

  • Obesity
  • Certain medical conditions:
    • Diabetes
    • Atherosclerosis—hardening of the arteries
    • Chronic kidney disease
    • Liver failure
    • Endocrine disorders
    • Prostatitis
    • Peripheral neuropathy
    • Peyronie's disease—bending of the penis caused by scar tissue
    • Neurological disorders such as multiple sclerosis , peripheral neuropathy, and stroke
    • High blood pressure
    • Psychiatric disorders, such as anxiety and depression
  • Surgery or injury to nerves:
    • Vascular surgery
    • Pelvic surgeries, particularly for prostate cancer
    • Spinal cord injury
  • Habits that may cause ED include:
    • Alcohol use
    • Illegal drug use
    • Anabolic steroid use
    • Heavy smoking
    • Relationship problems with a sexual partner
  • Side effect of medications such as:
    • Antihypertensives—for high blood pressure
    • Antihistamines—common as allergy medication
    • Antidepressants
    • Tranquilizers
    • Antipsychotics



Symptoms include:

  • A less firm penis
  • Fewer erections


You will be asked about your symptoms and medical history. A physical exam will be done. The doctor will ask about the quality and length of erections. Your answers may help the diagnosis.

Nocturnal penile tumescence testing will give the doctor more information. The test will check for erections while you sleep. If you have normal erections during sleep the cause may be emotional. If you have problems with an erection even while you sleep, the cause may be physical.

Other tests may be done to look for a cause:

  • Blood tests
  • Doppler imaging—to look at the blood flow in the penis.



Treatment options include:


Your doctor may prescribe:

  • Phosphodiesterase inhibitors—do not take these medications if you are also taking nitrates
  • Testosterone supplements—note: these supplements are only helpful if you have low testosterone levels
  • Alprostadil , either injected into the penis or inserted into the urethra as a suppository

Use caution and talk to your doctor before taking any over-the-counter medications for ED. Some of them may be unsafe.

Vacuum Devices

A vacuum device pulls blood into the penis. A band will then be placed around the penis to keep the erection. A vacuum device may include:

  • Plastic cylinder for the penis
  • Hand pump for pumping air out of the cylinder
  • Elastic band for holding the erection after removal of the cylinder

Vascular Surgery

Vascular surgery may be helpful for some. It is done to repair the blood vessel leaks.

Penile Implants

Implants may be placed in the penis. The implants can be inflated when needed to make an erection.

Penile Implant
penile implant smaller
Copyright © Nucleus Medical Media, Inc.

Sex Therapy

Sex therapy may help ED resulting from:

  • Unhelpful sexual techniques
  • Relationship problems
  • Anxiety
  • Depression


To reduce your chance of becoming impotent:

  • Follow treatment plans to manage blood pressure , diabetes, or depression.
  • Maintain a healthy weight .
  • Eat a healthful diet .
  • If you smoke, talk to your doctor about ways to quit . Smoking is significantly associated with ED in older men.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (ED; Impotence; Male Erectile Disorder)


Family Doctor—American Academy of Family Physicians 

Urology Care Foundation 


Canadian Urological Association 

Sex & U—The Society of Obstetricians and Gynaecologists of Canada 


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Erectile dysfunction. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: Updated March 28, 2012. Accessed September 7, 2017.

Viera A, Shenenberger D, Green G. Am Fam Physician. 1999;60(4):1159-1166.

What is erectile dysfunction? Urology Care Foundation website. Available at: Accessed September 7, 2017.