Electrolytes

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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Electrolytes Overview
• Sodium (Na)
• Conditions of Sodium Imbalance
• Symptoms of Sodium Imbalance
• Potassium (K)
• Conditions of Potassium Imbalance
• Calcium (Ca)
• Conditions of Calcium Imbalance
• Magnesium (Mg)
• Conditions of Magnesium Imbalance
• Bicarbonate (HCO3)
• Synonyms and Keywords
• Authors and Editors
• Read more on Electrolytes from Healthwise
• Viewer Comments: Electrolytes - Experience

Electrolytes Overview

Electrolytes are the smallest of chemicals that are important for the cells in the body to function and allow the body to work. Electrolytes such as sodium, potassium, and others are critical in allowing cells to generate energy, maintain the stability of their walls, and to function in general. They generate electricity, contract muscles, move water and fluids within the body, and participate in myriad other activities.

The concentration of electrolytes in the body is controlled by a variety of hormones, most of which are manufactured in the kidney and the adrenal glands. Sensors in specialized kidney cells monitor the amount of sodium, potassium, and water in the bloodstream. The body functions in a very narrow range of normal, and it is hormones like renin (made in the kidney), angiotensin (from the lung, brain and heart), aldosterone (from the adrenal gland), and antidiuretic hormone (from the pituitary) that keep the electrolyte balance within those normal limits.

Keeping electrolyte concentrations in balance also includes stimulating the thirst mechanism when the body gets dehydrated.

Sodium (Na)

Sodium is most often found outside the cell, in the plasma (the non-cell part) of the bloodstream. It is a significant part of water regulation in the body, since water goes where the sodium goes. If there is too much sodium in the body, perhaps due to high salt intake in the diet (salt is sodium plus chloride), it is excreted by the kidney, and water follows.

Sodium is an important electrolyte that helps with electrical signals in the body, allowing muscles to fire and the brain to work. It is half of the electrical pump at the cell level that keeps sodium in the plasma and potassium inside the cell.

Conditions of Sodium Imbalance

Hypernatremia (hyper= too much + natr= sodium + emia=in the blood) is usually associated with dehydration, and instead of having too much sodium, there is too little water. This water loss can occur from illnesses with vomiting or diarrhea, excessive sweating from exercise or fever, or from drinking fluid that has too high concentrations of salt.

Hyponatremia (hypo=too little) is caused by water intoxication (drinking so much water that it dilutes the sodium in the blood and overwhelms the kidney's compensation mechanism) or by a syndrome of inappropriate anti-diuretic hormone secretion (SIADH). SIADH can be associated with illnesses like pneumonia, brain diseases, cancer, thyroid problems, and some medications.