Dr. Oz and Oprah talk about impotence.

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Question 8: Impotence could be a sign of what health problem?
A) Liver problems
B) Heart disease
C) Iron deficiency
D) Underactive thymus

The correct answer is B.

Erections happen when arteries in the penis dilate and blood flows in. This dilation is caused by the release of a gas called nitric oxide. "If you don't have enough of that gas [to have an erection], it's not present in other places either—including your heart. It's one of the first signs that the heart is having hardened arteries."

In fact, Dr. Oz says that drugs that treat erectile dysfunction stimulate chemicals that ultimately release nitric oxide. "That stated," Dr. Oz says, "the best solution is to keep your nitric oxide levels healthy. And the way for us to do that is to keep our arteries healthy."