By James M. Rippe

In the vast majority (more than 90 percent) of people with high blood pressure, physicians aren’t able to determine its exact cause. In medical terms, this condition is known as primary or idiopathic hypertension. That’s not to say that physicians are idiots, but that they haven’t yet figured out the precise mechanisms, functions, or agents that cause hypertension.

Primary hypertension is also termed essential high blood pressure. In the same way that idiopathic doesn’t mean that doctors are idiots, neither does essential mean that having hypertension is essential. Quite the contrary! Treating it is what is essential! Look at some of the factors that appear to contribute to hypertension.

  • Salt intake: Among the theories about what causes primary high blood pressure, most relate to problems that your kidneys appear to have with handling excess salt. Population studies show that societies in which people consume large amounts of salt (such as the United States) have a correspondingly high incidence of high blood pressure.

    Similarly, in cultures where salt intake is low, the incidence of high blood pressure is extremely low. Other studies show that for most people with hypertension, restricting salt intake helps lower high blood pressure.

  • Inherited predisposition: Hypertension also appears to have a genetic component. Some people may be genetically predisposed to have high blood pressure. However, although hypertension runs in some families, these tendencies may actually result as much from shared lifestyles as they do from shared genetic backgrounds.

    Doctors certainly know that lifestyle factors, such as obesity (and abdominal obesity, in particular), inactivity, cigarette smoking, and high alcohol consumption all are associated with increased risk of hypertension.

  • Known conditions that cause it: In approximately 10 percent of the people with hypertension, the specific underlying cause can be discovered. This condition is known as secondary hypertension, meaning it’s a secondary result of a separate primary condition. If the underlying condition can be treated and corrected, then secondary hypertension usually is corrected, too. Conditions known to cause secondary high blood pressure include

    • Narrowing of the arteries that supply the kidneys

    • Other diseases of the kidneys

    • Abnormalities in the endocrine system, such as overactive adrenal glands or a benign tumor in the adrenal glands that secretes a hormone that raises blood pressure.

    • Transient conditions such as pregnancy for certain women

    • Certain medications that can increase the risk of high blood pressure, such as oral contraceptives or estrogen replacement therapy following menopause

If you’re diagnosed with high blood pressure, your doctor will explore any of these potential underlying causes for hypertension prior to making the diagnosis.