Additional information is available at the end of the chapter http://dx.doi.org/10.5772/57174 . IntroductionErectile dysfunction ED or male impotence is a sexual dysfunction characterized by the inability to develop or maintain an erection of the penis [ ]. There are various underlying causes, such as a compromised cardiovascular system and diseases such as diabetes and chronic kidney disease CKD , many of which are medically treatable. The causes of erectile dysfunction may be physiological or psychological [ ]. Sexual function includes libido, penile erection, ejaculation, and orgasm. While each of these parameters may be of concern to an individual patient, the vast majority of men complain of ED. Testosterone deficiency frequently is associated with decreased libido and ED. ED is a clinical problem that is underdiagnosed, under-evaluated, and under-treated. The prevalence of ED increases with age, and it is associated with multiple medical conditions including diabetes, hypertension, and heart disease that also increase with age. ED is a highly prevalent and often underreported condition. The prevalence of ED varies in different countries and approximately million men worldwide are estimated to be affected with ED. More than half of US men between the ages of and years are estimated to have ED. The worldwide ED prevalence in men with diabetes ranges from % to % and it is estimated that the prevalence of ED will double in the next years [ ]. There is a strong link between ED and atherosclerotic disease due to the fact that they share similar risk factors. In a study where patients referred for myocardial perfusion single-photon emission computed tomography were screened for ED with a questionnaire, it was found out that . % of the patients had ED. Patients with ED showed more severe coronary heart disease. In diabetic patients, ED has been shown to predict silent coronary artery disease, and in asymptomatic men without cardiovascular risk factors or