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The information contained on this page is provided as general health information and is not intended to substitute as medical advice and direction from your physician or health care provider. Please direct any questions related to your health care provider. In an emergency, call 9-1-1 or go to the nearest emergency center.


Electrolytes

Definition

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:

  • Calcium
  • Chloride
  • Magnesium
  • Phosphorus
  • Potassium
  • Sodium

Electrolytes can be acids, bases, or salts. They can be measured by different blood tests. Each electrolyte can be measured separately, such as:

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.

References

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.