Male Reproductive Medicine and Surgery Program

Erectile Dysfunction

erectile dysfunction


Erectile dysfunction, or impotence, is the inability to get and keep an erection sufficient for intercourse. It is estimated that over 50 percent of men in the U.S. suffer from ED. Years ago it was thought that most causes of ED were psychological. We now know that most causes of ED are physical (90 percent).

Physiology of Erection

An erection occurs after sexual stimulation causes causing a relaxation of smooth muscle cells in the penis which allows an increase of blood flow into the penis. A normal erection allows a temporary trapping of blood to maintain an erection.



Erectile dysfunction may cause stress, cause relationship problems, affect self-confidence, and impair the ability to achieve a pregnancy.

Evaluation and treatment

Evaluation will include a comprehensive history and physical examination and assessment of serum hormones. Penile doppler ultrasound may be utilized to aid in the assessment of the penile soft tissue and blood vessel anatomy. Treatments are tailored to patients’ needs and are aimed at improving a sexual function and satisfaction.


Stanford Medicine Resources:

Footer Links: