High blood pressure, Hypertension

High blood pressure (hypertension) is the most frequent classic cardiovascular risk factor and accounts for a large proportion of cardiovascular mortality, the main cause of death worldwide. Hypertension is generally classified as primary (essential) or secondary. Essential hypertension (EH) is the most common diagnosis in this disease, suggesting that a monocausal etiology has not been identified. However, a number of risk factors associated with EH have also been identified such as age, sex, demographic, environmental, genetic, and vascular factors. Secondary hypertension generally has an earlier age at onset, no family history, and a clear cause such as a renal or endocrine disorder, or an iatrogenic trigger, such as use of oral contraceptives. Blood pressure is a heritable trait; an estimated 30% of variance in blood pressure relates to genetic factors. Understanding of the genetic architecture of traits has progressed in rare mendelian hypertensive phenotypes, such as Gordon's syndrome.