What is a potassium blood test?A potassium blood test measures the amount of potassium in your blood. Potassium is a type of electrolyte. Electrolytes are electrically charged minerals in your body that help control muscle and nerve activity, maintain fluid levels, and perform other important functions. Your body needs potassium to help your heart and muscles work properly. Potassium levels that are too high or too low may indicate a medical problem.Other names: potassium serum, serum potassium, serum electrolytes, K
