Potassium is a mineral that is found in many foods. It keeps the heart beating regularly, helps to maintain fluid balance, and allows the nerves and muscles to work properly.
Sodium is an element that is found in many foods as well as water. The body requires a small amount of sodium in the diet to control blood pressure and blood volume. However, most people consume many times the amount of sodium needed. A healthy level of sodium in the diet contains fewer than 2.3 grams (2300 milligrams, or about the amount of sodium in one teaspoon) of sodium each day.
The kidneys are the main organ that controls the correct level of sodium and potassium in the blood. People who take certain medicines or who have chronic kidney disease must sometimes, under the direction of their clinician, limit the amount of sodium and potassium in their diet to keep their potassium level close to normal.