Electrolytes

Electrolytes are minerals that dissociate into positively and negatively charged ions in body fluids and other solutions. In biological systems they conduct electrical currents and help regulate fluid balance, nerve signaling, and muscle contraction. Electrolyte balance depends on intake, distribution between compartments, and losses through urine, sweat, and stool. The body maintains distinct extracellular and intracellular pools, with transport proteins and membranes controlling their distribution.

Common extracellular electrolytes include sodium, chloride, and bicarbonate, which together help set osmotic pressure and pH. The major intracellular cation is potassium; calcium and magnesium are also essential for muscle function, nerve transmission, and enzyme activity. Phosphate and sulfate participate in energy metabolism and buffering. Most electrolytes exist as ions in solution and influence membrane potentials, signaling pathways, and acid–base balance.

Kidneys are central to electrolyte regulation, adjusting excretion to maintain steady levels. Hormones such as aldosterone, antidiuretic hormone, and parathyroid hormone influence sodium, potassium, calcium, and phosphate handling. Water balance and thirst drive intake; losses due to illness, medications, or sweating can disrupt electrolyte status rapidly.

Clinical electrolyte disturbances are common and may require laboratory testing and treatment. A serum electrolyte panel (often part of a basic or comprehensive metabolic panel) measures sodium, potassium, chloride, bicarbonate, calcium, magnesium, and phosphate. Treatments range from oral rehydration and dietary adjustments to intravenous fluids and targeted electrolyte supplementation, depending on the underlying cause and severity.