Classic and modern tools of genetics have been applied to hypertension research for some 20 years. This volume in the Handbook of Hypertension series aims to go beyond a simple summary of discoveries and provides a critical commentary on many controversial issues. It will be particularly useful for clinician scientists at all stages of their careers, graduate students and post-doctoral scientists as well as all those interested in cardiovascular medicine and research throughout the entire spectrum from bench to bedside. As in every relatively young area of research, the initial excitement over the early positive observations has not always been confirmed by subsequent larger studies with greater statistical power. Issues related to current recommendations on design of studies and their analysis are therefore included. Pharmacogenetics and pharmacogenomics have been the subjects of many debates in recent years and are of particular importance in hypertension as life-long treatments, frequently with multiple drugs are given to millions of people world-wide. A critical appraisal of this controversial topic is provided. Several chapters on experimental genetics of hypertension with a special focus on physiological genomics are also included.