Salt Sensitivity

One reason why high blood pressure runs in families may be an inherited sensitivity to salt. When we eat a lot of salt, our kidneys get rid of it. But in many people the kidneys, otherwise working normally, can't get rid of all the salt. When this happens, extra water stays in your blood to dilute the salt. This leads to extra blood volume, which in turn leads to high pressure in the blood vessels, hence high blood pressure.

Salt sensitivity can occur in anyone, but some groups of people need to pay particularly close attention to the damaging effects of salt. For instance, as many as 70 percent of African American with hypertension are also salt-sensitive. Hypertension occurs twice as often in blacks, develops earlier, and is more severe for African Americans than any other group of people. By the time they are 65, nearly 50 percent of black men and 60 percent of black women have high blood pressure. African Americans can protect themselves from this damaging disease just by being aware of their risk and keeping risk factors - and blood pressure - under control.

There is no easy test to see if you are salt-sensitive. The best way to see if your blood pressure is affected by salt is to stop eating sodium completely and see if your blood pressure goes down.

While sodium very likely raises blood pressure, other nutrients - potassium, calcium, and magnesium - may lower blood pressure. There is not yet a definite cause-and-effect known, but we do know that all three certainly affect how blood vessels constrict. In addition, calcium and potassium interact with sodium, possibly protecting the blood vessels from sodium's deleterious effects.