Electrolytes are ionized molecules found throughout the blood, tissues, and cells of the body. These molecules, which are either positive (cations) or negative (anions), conduct an electric current and help to balance pH and acid-base levels.
Electrolyte measurements may be used to help investigate conditions that cause electrolyte imbalances such as dehydration, kidney disease, lung diseases, or heart conditions.
The electrolyte panel typically includes tests for:
Sodium (Na)—most of the body's sodium is found in extracellular fluid, outside of the body's cells, where it helps to regulate the amount of water in the body.
Potassium (K)—is found mainly inside the body's cells. A small but vital amount of potassium is found in the plasma, the liquid portion of the blood. Monitoring potassium is important as small changes in the potassium level can affect the heart's rhythm and ability to contract.
Calcium (Ca) — A positive electrolyte, that affect neuromuscular performance and contributes to skeletal growth and blood coagulation.
Magnesium (Mg) — Influences muscle contractions and intracellular activity.
Chloride—this electrolyte moves in and out of the cells to help maintain electrical neutrality and its level usually mirrors that of sodium.
Bicarbonate (HCO3)—the main job of bicarbonate (or total CO2, an estimate of bicarbonate), which is released and reabsorbed by the kidneys, is to help maintain a stable pH level (acid-base balance) and, secondarily, to help maintain electrical neutrality. Bicarbonate insufficiencies and elevations cause acid-base disorders (i.e., acidosis, alkalosis).
Phosphate (HPO4) —Negative electrolyte that impacts metabolism and regulates acid-base balance and calcium levels.
The most common cause of high potassium is impaired kidney function. Other causes of hyperkalemia include:
Certain medications, such as angiotensin-converting enzyme (ACE) inhibitors, Angiotensin Receptor Blocker (ARB) Heparin, Bactrim.
Hormone deficiencies, including adrenal failure (Addison's disease)
Destruction of red blood cells due to severe injury or burns
Excessive use of potassium supplements
True hyperkalemia is a serious and potentially life-threatening disorder. It can cause:
Abnormal heart rhythms (arrhythmias)
Low potassium may result from many different conditions. The most common cause is excessive potassium loss in the urine or from the gastrointestinal tract, such as due to:
Use of diuretics
Excessive use of laxatives
Severe vomiting or diarrhea
Signs and symptoms of low potassium may include:
Certain kidney diseases such as renal tubular acidosis
A very low potassium level is life-threatening.
The most common cause is hyperparathyroidism. Other causes of hypercalcemia include:
Certain medications, such as lithium or thiazide diuretics
Certain cancers, including breast, lung and certain blood cancers
Sarcoidosis, an inflammatory disorder
Excessive intake of calcium or vitamin D supplements
Familial hypocalciuric hypercalcemia, a genetic disorder
Dialysis for chronic kidney failure
Adrenal gland failure
Severe hypercalcemia may cause:
Lethargy and fatigue