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Electrolytes
Electrolytes are substances that become ions in solution and acquire the capacity to conduct electricity. The balance of the electrolytes in our bodies is essential for normal function of our cells and our organs.

Common electrolytes that are measured by doctors with blood testing include sodium, potassium, chloride, and bicarbonate.

Sodium (Na)
Sodium is the major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. Excess sodium (such as from fast food hamburger and fries) is excreted in the urine. Sodium regulates the total amount of water in the body and the transmission of sodium into and out of individual cells also plays a role in critical body functions. Many processes in the body, especially in the brain, nervous system, and muscles, require electrical signals for communication. The movement of sodium is critical in generation of these electrical signals. Too much or too little sodium therefore can cause cells to malfunction, and extremes (too much or too little) can be fatal.

Potassium (K)
Potassium is the major positive ion (cation) found inside of cells. The chemical notation for potassium is K+. The proper level of potassium is essential for normal cell function. Among the many functions of potassium in the body are regulation of the heartbeat and function of the muscles. A seriously abnormal increase of potassium (hyperkalemia) or decrease of potassium (hypokalemia) can profoundly affect the nervous system and increases the chance of irregular heartbeats (arrhythmias), which, when extreme, can be fatal.

Chloride (Cl)
Chloride is the major anion (negatively charged ion) found in the fluid outside of cells and in blood. An anion is the negatively charged part of certain substances such as table salt (sodium chloride or NaCl) when dissolved in liquid. Sea water has almost the same concentration of chloride ion as human fluids. Chloride also plays a role in helping the body maintain a normal balance of fluids.

The balance of chloride ion (Cl-) is closely regulated by the body. Significant increases or decreases in chloride can have deleterious or even fatal consequences:

- Increased chloride (hyperchloremia): Elevations in chloride may be seen in diarrhea, certain kidney diseases, and sometimes in overactivity of the parathyroid glands.
- Decreased chloride (hypochloremia): Chloride is normally lost in the urine, sweat, and stomach secretions. Excessive loss can occur from heavy sweating, vomiting, and adrenal gland and kidney disease.

Bicarbonate (HC03)
The bicarbonate ion acts as a buffer to maintain the normal levels of acidity (pH) in blood and other fluids in the body. Bicarbonate levels are measured to monitor the acidity of the blood and body fluids. The acidity is affected by foods or medications that we ingest and the function of the kidneys and lungs. The chemical notation for bicarbonate on most lab reports is HCO3- or represented as the concentration of carbon dioxide (CO2).