Health Authority

Two forms of hypertension have been described: essential (or primary) hypertension and secondary hypertension. Essential hypertension is a condition much more common and accounts for 95% of hypertension. The cause of essential hypertension is multifactorial, that is, there are several factors that combined the effects of hypertension. In secondary hypertension, accounting for 5% of hypertension, hypertension is secondary to (caused by) a specific abnormality in one of its organs or body systems. (Secondary hypertension is discussed in a separate section.)







Essential hypertension affects approximately 72 million Americans, but its basic causes or underlying defects are not always known. However, some associations have been detected in people with essential hypertension. For example, essential hypertension develops only in groups or companies that have a relatively high salt consumption, more than 5.8 grams per day. Salt intake may be particularly important in relation to essential hypertension in several situations, and excess salt may be involved in hypertension that is associated with age, the U.S. African origin, obesity, heredity ( genetic) susceptibility, and renal failure (kidney failure). The Institute of Medicine of the National Academies recommends that healthy adults between 19 and 50 consume only 3.8 grams of salt to replace the average daily amount of loss through sweat and to achieve a diet that provides enough essential nutrients.

Genetic factors believed to play an important role in the development of hypertension. However, the genes of hypertension has not yet been identified. (Genes are small segments of chromosomes, which produce proteins that determine the characteristics of individuals.) Current research in this area has focused on genetic factors that affect the renin-angiotensin-aldosterone system. This system helps to regulate blood pressure by controlling salt balance and the tone (state of elasticity) of blood vessels.

About 30% of cases of hypertension due to hereditary factors. For example, the U.S. prevalence of hypertension is higher among African Americans than among Caucasians or Asians. In addition, people who have one or two older, hypertension, high blood pressure is twice as common in the general population. Rarely, certain unusual genetic disorders affecting the hormones of the adrenal glands can lead to hypertension. (These identified genetic disorders considered of secondary hypertension.)

The majority of patients with hypertension is particularly common abnormality of the arteries: an increased resistance (stiffness or lack of elasticity) is small blood vessels, which are farthest from the heart (peripheral arteries or arterioles). The arterial blood products containing oxygen and nutrients to all body tissues. In the arteries is related to the tissue capillaries, veins (venous system), which restores blood circulation and lungs. Just what makes the peripheral arteries harden not known. However, this rigidity of the peripheral arteries is present in people with hypertension linked to genetic factors, obesity, sedentary lifestyle, excess salt, and aging. The inflammation may also be relevant to hypertension, as expected, the development of hypertension in the presence of elevated levels of C-reactive protein (a marker of inflammation blood test), and in some individuals.