Electrolytes are minerals in your blood and other body fluids that carry an electric charge.
Electrolytes affect how your body functions in many ways, including:
- The amount of water in your body
- The acidity of your blood (pH)
- Your muscle function
- 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, or salts. They can be measured by different blood tests. Each electrolyte can be measured separately, such as:
- Ionized calcium
- Serum calcium
- Serum chloride
- Serum magnesium
- Serum phosphorus
- Serum potassium
- Serum sodium
Note: Serum is the part of blood that doesn’t contain cells.
Sodium, potassium, and chloride levels can also be measured as part of a basic metabolic panel. A more complete test, called comprehensive metabolic panel, can test for these several more electrolytes.
The electrolytes – urine test measures electrolytes in urine. It tests the levels of calcium, chloride, potassium, sodium, and other electrolytes.
Chernecky CC, Berger BJ. Electrolytes panel – blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:464-467.
DuBose TD. Disorders of acid-base balance. In: Skorecki K, Chertow GM, Marsden PA, Taal MW, Yu ASL, eds. Brenner and Rector’s The Kidney. 10th ed. Philadelphia, PA: Elsevier; 2016:chap 17.