Although he is renowned in medical circles as "the father of Viagra," the discoveries of Louis Ignarro have profound implications for all circulatory conditions, not least heart disease, the leading cause of death around the world. Nitroglycerin has been used in treating heart disease since the 1870s, but for over a century no one knew what property of the chemical causes constricted blood vessels to dilate. Ignarro determined that nitroglycerin, and other nitrates and nitrites, are metabolized as nitric oxide, relaxing the smooth muscle surface of the blood vessels, and inhibiting the growth of blood platelets. He was the first to observe that nitric oxide is a neurotransmitter mediating erectile function, a discovery that led to the creation of Viagra and other drugs for impotence, as well as nutritional supplements that improve cardiovascular health and athletic performance. Louis Ignarro embarked on his journey of discovery from humble beginnings. Born in Brooklyn, New York to working-class immigrant parents, he received the Nobel Prize in Medicine in 1998. As he told a Congressional committee, "Only in America could the son of an uneducated carpenter win the Nobel Prize in Medicine." In this podcast, recorded at the 2014 International Achievement Summit in San Francisco, he recounts the career path that led to his groundbreaking discoveries.