What causes an erection?

When you are sexually stimulated, your brain sends nerve signals to the penis, causing the muscles in the penis to relax and let blood flow into it. The penis becomes larger and firmer, like an inflated balloon. The veins in the penis are then closed off to trap the blood. After climax or after the sexual arousal has passed, the veins open up and blood flows back into the body.

What causes erectile dysfunction?

ED is most often caused by health problems that require treatment to help prevent more serious complications. Some of the problems that can cause ED are

• high blood pressure
• high cholesterol
• diabetes
• alcohol or drug abuse
• some prescription drugs
• unhealthy habits like smoking, overeating, and not exercising
• treatments for prostate cancer
• an injury or disease that affects the nerves

How is erectile dysfunction treated?

Lifestyle changes-including exercising more, quitting smoking, losing weight, and cutting back on alcohol-may solve the problem. If you have made these changes and still have erection problems, your doctor can offer a number of other treatments. Treatment may include

• Counseling. Even though most cases of ED have a physical cause, counseling can help couples deal with the emotional effects.

• Oral medication. Your doctor may prescribe a pill to treat ED. Current brands include Viagra, Levitra, and Cialis. These drugs work by increasing blood flow to the penis. Do not take any of these drugs if you are taking nitrates, a type of heart medicine.

• Injection. Medicines injected into the shaft of the penis or inserted into the tip of the penis usually cause an erection within minutes.

• Vacuum device. A vacuum tube inserted over the penis can create an erection. As air is pumped out of the tube, the penis expands and blood flows into it. After the tube is removed, a specially designed rubber band is placed at the base of the penis to keep the blood from flowing out.

• Penile implant. If other options fail, a surgeon can implant a device into the penis that inflates or can be straightened to create an erection.

Where can I get more information about erection problems?

National Kidney and Urologic Diseases Information Clearinghouse
3 Information Way
Bethesda, MD 20892–3580
Phone: 1–800–891–5390
TTY: 1–866–569–1162
Fax: 703–738–4929
Email: nkudic@info.niddk.nih.gov
Internet: www.kidney.niddk.nih.gov

The National Kidney and Urologic Diseases Information Clearinghouse is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health of the U.S. Department of Health and Human Services.

This publication is not copyrighted. The Clearinghouse encourages people to duplicate and distribute as many copies as desired.

The NIDDK Awareness and Prevention Series is designed to make you ask yourself, “Could this be me or someone I care for?” So take a closer look. Additional information on this topic and other titles in the series are available through the National Kidney and Urologic Diseases Information Clearinghouse or on the Internet at www.urologic.niddk.nih.gov.

NIH Publication No. 08-6176
December 2007

Page last updated: September 2, 2010