The electrolytes are related to fluid balance in your cells. They are especially important if you become dehydrated or have kidney problems. Sodium levels indicate your balance of salt and water. They also are a sign of the functioning of your kidneys and adrenal glands. They can also occur when the heart is not pumping blood normally, or when the kidneys are not working properly.
Potassium affects several major organs including the heart.
Potassium levels rise in kidney failure, and may be abnormal due to vomiting or diarrhea. Chloride levels often go up and down along with sodium levels. This is because sodium chloride, or common salt, is a major component of blood. Bicarbonate or CO2 measures a buffer system in the blood. A normal CO2 level keeps the blood acidity at the correct level.