Electrolytes are minerals in your blood and other body fluids that carry an electric charge.
Electrolytes affect the amount of water in your body, the acidity of your blood (pH), your muscle function, and other important processes. You lose electrolytes when you sweat. You must replace them by drinking fluids that contain electrolytes. Water does not contain electrolytes.
Common electrolytes include:
Electrolytes can be acids, bases, and salts.
They can be measured by laboratory studies of the blood in different ways. Each electrolyte can be ordered as a separate test, such as:
Note: Serum is the part of blood that doesn't contain cells.
Sodium, potassium, and chloride can also be ordered as part of an electrolyte panel, a basic metabolic panel or a comprehensive metabolic panel.
The electrolytes - urine test measures electrolytes in urine. It usually measures the levels of calcium, chloride, potassium, or sodium.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.