01/29/2009 05:12 am ET | Updated Nov 17, 2011

Health Tip: Why You May Have Erectile Dysfunction

Erectile dysfunction occurs when a man can't achieve or maintain an erection during sex.

The American Academy of Family Physicians says the condition doesn't have to be a natural part of getting older. ED often is attributed to physical or psychological causes. Physical reasons may include:

* Having a side effect of surgery on the prostate or bladder, or radiation therapy to the testicles.
* Having low testosterone levels, kidney failure, liver failure, multiple sclerosis or Parkinson's disease.
* Having chronic conditions such as diabetes, high blood pressure, or hardening of the arteries.
* Having had a stroke or an injury to the brain or spinal cord.
* Using too much tobacco or alcohol.
* Being tired.

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