Hypertension is quantitatively the major cardiovascular risk factor and responsible for ~50% of cardiovascular morbidity and mortality. Blood pressure is also a classical complex genetic trait with heritability estimates of 30-50%. Whereas blood pressure regulation is known in much detail, the intrinsic origin of essential hypertension remains obscure although many environmental factors are known. Analyses on rare monogenic hypertension syndromes have been extremely instructive leading to pathways that involve kidney salt handling, the renin-angiotension system, and corticoid pathways. The genetic basis of common essential hypertension on the other hand is only becoming accessible recently by methods of high-throughput genotyping. Unbiased genome-wide analyses of blood pressure genomics have identified 43 loci associated with blood pressure traits. We now know that in total there are hundreds of such loci having small effects on blood pressure, opening a perspective on the genetic architecture of blood pressure that was unknown before.