Potassium. Potassium concentrations that are too high can be due to kidney disease or drugs that can decrease potassium excretion from the body. Low potassium can be a consequence of using certain diuretics or of dehydration. Normal potassium levels are 3.5 to 5.0 mmol/L.nderstanding Electrolytes. The balance of sodium, potassium, chloride and bicarbonate in the blood is a good indicator of how well the kidneys and heart are functioning. Knowing which electrolytes are out of balance can help your doctor determine a course of treatment.