Sodium plays a critical role in regulating proper water distribution and blood pressure. Abnormally low or high levels of sodium in the blood usually are associated with heart or kidney disease rather than dietary deficiency or excess.
A high sodium intake may lead to extracellular volume expansion and an increased expression of the renal sodium pump via release of a digitalis-like factor. Increased activity of the renal sodium pump, also stimulated by long term potassium depletion, promotes sodium retention.
The most abundant mineral inside human body’s cells is potassium. Therefore they need a fair amount of potassium in their food. Potassium can affect hyperextension, but in a different way compared with sodium.
Many studies suggest that potassium intake is inversely related to systolic and diastolic blood pressure; potassium deficiency may play a special role in the high incidence and prevalence of hypertension.
If people with hypertension eat a diet rich in potassium containing foods such as fruits and vegetables, their blood pressure often improves.
Sodium and potassium: risk factor for hypertension