While an enlarged prostate has its own constellation of health issues, treating the condition can result in new problems. In partnership with scientists from Denmark and Germany, urologists at the Boston University School of Medicine have found that taking a particular class of medication to treat benign prostatic hyperplasia (BPH) can lower the male libido.

BPH occurs when the prostate begins to enlarge. This process occurs in most men over time. By the age of 40, many men have BPH, and by age 90 more than 80 percent of men have an enlarged prostate, according to the National Institutes of Health (NIH).

In the Journal of Sexual Medicine, the international research team reported that a medication group called 5a-reductase inhibitors can reduce this enlargement. However, they found that it tends to cause erectile dysfunction.

This is not the first time the medication has been associated with low libido. A study in the New England Journal of Medicine came to a similar conclusion in 1992.

The authors of the new paper concluded that doctors should explicitly mention this side effect when suggesting the use of 5a-reductase inhibitors.

In addition to taking prescription drugs, men with prostate trouble may consider taking natural saw palmetto extract, which may reduce prostate size and increase urinary flow.