Erectile dysfunction (ED) is the inability to attain or maintain an erection of the penis that is firm enough for sexual intercourse.

To initiate and maintain an erection, the penis must fill with blood. One type of blood vessel opens wide to allow blood into the penis. Meanwhile, a second type of blood vessel squeezes down to keep the blood from leaving the penis. Nerve signals cause the proper changes in the blood vessels.


The following factors can cause erectile dysfunction:

Venous Leak

The blood vessels that keep the blood from leaving the penis may be injured or have disease. This can cause a leak in these vessels. Blood can escape through these leaks during an erection. This means that an erection cannot occur or may not last long.

Neurovascular Function

Problems with the nerves and blood vessels can cause ED. Conditions that can cause problems include:

  • Nerve dysfunction—can reduce feeling in the penis, resulting in ED
  • Diabetes—interferes with nerve signals
  • Atherosclerosis —can cause reduced blood flow
  • Peripheral neuropathy , spinal cord injury, and surgery—can damage nerves
  • Side-effects from medications—interferes with proper functioning of the blood vessels
  • Blood Vessels and Nerves of the Male Pelvis

    Nerves, blood vessels, penis

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  • Psychological Factors

    Many of the nerve signals needed for an erection come from the brain. Emotional problems may play a role 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
  • Arteriosclerosis—hardening of the arteries
  • Chronic kidney disease
  • Liver failure
  • Endocrine disorders
  • Prostatitis
  • 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
  • Traumatic conditions:     
  • Vascular surgery
  • Pelvic surgeries, particularly for prostate cancer
  • Spinal cord injury
  • Behaviors:     
  • Alcohol use
  • Illegal drug use
  • Anabolic steroid use
  • Heavy smoking
  • Interpersonal conflicts with a sexual partner
  • Medications:     
  • Antihypertensives—for high blood pressure
  • Antihistamines—common as allergy medication
  • Antidepressants
  • Tranquilizers
  • Antipsychotics
  • Symptoms

    Symptoms include:

  • A less firm penis
  • Fewer erections
  • Diagnosis

    You will be asked about your symptoms and medical history. A physical exam will be done. Expect questions about the frequency, quality, and duration of your erections. Your answers may help the diagnosis.

    Your bodily fluids may be tested. This can be done with blood tests.

    Nocturnal Penile Tumescence Testing

    This test will monitor erections while you sleep. Involuntary erections during sleep are normal. If you have ED but have normal erections during sleep, the problem may be emotional. If you have problems with an erection even while you sleep, the problem may be physical.


    Doppler imaging is used to look at the blood flow. The test is done to check for blood flow in the penis. It will also look for blockage in the arteries or veins that supply the penis.


    Treatment options include:


    Your doctor may prescribe:

  • Phosphodiesterase inhibitors     

    Do not take these medications if you are also taking nitrates.

  • Oral testosterone , 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 is done to repair the blood vessel leaks. This has been shown to be effective in some cases.

    Penile Implants

    Implants may be placed in the penis. The implants can be inflated to simulate an erection.

  • Penile Implant

    penile implant smaller

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  • Sex Therapy

    Sex therapy may help ED resulting from:

  • Ineffective sexual techniques
  • Relationship problems
  • Anxiety
  • Depression
  • Prevention

    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.