Erectile Dysfunction (ED, Impotence)

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Erectile Dysfunction Causes and Symptoms

There are many causes of erectile dysfunction (impotence) and some include:

  • blood vessel diseases (such as peripheral vascular disease and others),
  • systemic disease,
  • hormonal imbalance, and
  • medications (such as blood pressure and heart medications).

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Erectile dysfunction (impotence) facts

What is erectile dysfunction (ED)?

Erectile dysfunction (ED), also known as impotence, is the inability to achieve or sustain an erection for satisfactory sexual activity. Erectile dysfunction is different from other conditions that interfere with male sexual intercourse, such as lack of sexual desire (decreased libido) and problems with ejaculation and orgasm (ejaculatory dysfunction). ED affects about 50% of men aged 40 and over. This article focuses on the evaluation and treatment of erectile dysfunction.

What are erectile dysfunction symptoms and signs?

Symptoms of erectile dysfunction may include the following:

  • Penile erection occurs but it is not maintained for the length of sexual activity
  • Penile erection that is not firm enough to penetrate the vagina
  • Inability to obtain a penile erection

What is normal penis anatomy?

The penis contains two chambers, called the corpora cavernosa, which run the length of the upper side of the penis (see figure 1 below). The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa. Filling the corpora cavernosa is a spongy tissue consisting of smooth muscles, fibrous tissues, veins, and arteries. A membrane, called the tunica albuginea, surrounds the corpora cavernosa. Veins located in the tunica albuginea drain blood out of the penis. The corpus spongiosum helps maintain the urethra open during an erection for passage of the ejaculate (sperm and prostatic fluid).

Picture of arteries and veins involved in erectile dysfunction (ED)
Picture of arteries and veins involved in erectile dysfunction (ED); SOURCE: NIH
Medically Reviewed by a Doctor on 2/25/2016

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