Overview of Electrolytes & Electrolyte Imbalances

Electrolytes are salts that conduct electricity and are found in the body fluid, tissue, and blood. Examples are chloride, calcium, magnesium, sodium, and potassium. Sodium (Na+) is concentrated in the extracellular fluid (ECF) and potassium (K+) is concentrated in the intracellular fluid (ICF). Proper balance of electrolytes is essential for muscle coordination, heart function, fluid absorption and excretion, nerve function, and concentration.

The kidneys regulate fluid absorption and excretion and maintain a narrow range of electrolyte fluctuation. Normally, sodium and potassium are filtered and excreted in the urine and feces according to the body's needs. Too much or too little sodium or potassium, caused by poor diet, dehydration, medication, and disease, results in an imbalance. Too much sodium is called hypernatremia, and too little is called hyponatremia. Too much potassium is called hyperkalemia, and too little is called hypokalemia.

Electrolyte Imbalance Incidence and Prevalence

Hyponatremia is the most common electrolyte imbalance. It is associated with kidney disease such as nephrotic syndrome and acute renal failure (ARF).

Men and women with healthy kidneys have equal chances of experiencing electrolyte imbalance, and people with an eating disorder such as anorexia or bulimia—which affect women more often—are at increased risk. Very young children and older adults are affected more often than young adults.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 30 Apr 2001

Last Modified: 28 Oct 2014