What is being tested?Electrolytes are electrically charged minerals that are found in body tissues and blood in the form of dissolved salts. They help move nutrients into and wastes out of the body’s cells, maintain a healthy water balance, and help stabilize the body’s pH level. The electrolyte panel measures the main electrolytes in the body: sodium (Na+), potassium (K+), chloride (Cl-), and carbon dioxide (total CO2).
Most sodium is found in the plasma, outside of the body’s cells, where it helps to regulate the amount of water in your body. Potassium is found primarily 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. Small changes in the K+ level can affect the heart’s rhythm and ability to contract. Chloride travels in and out of the cells to help maintain electrical neutrality, and its level usually mirrors that of sodium. The CO2 portion of the electrolyte panel measures mainly bicarbonate. The primary role of bicarbonate, which is excreted and reabsorbed by the kidneys, is to help maintain a stable pH level (acid-base balance) and, secondarily, to help maintain electrical neutrality.
Your diet provides sodium, potassium, and chloride; your kidneys excrete them. Your lungs provide oxygen and regulate CO2. The balance of these chemicals is an indication of the functional well-being of several basic body functions, including those performed by the kidneys and heart.
The electrolyte panel is composed of the individual tests for sodium, potassium, chloride, and total carbon dioxide. A related "test" is the anion gap, which is actually a value calculated using the results of an electrolyte panel. The occurrence of an abnormal anion gap is non-specific but can suggest certain kinds of metabolic abnormalities, such as starvation or diabetes, or the presence of a toxic substance, such as oxalate, glycolate, or aspirin. For more information on anion gap, click here.
