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Electrolytes 101

Electrolyte Imbalances

The most common electrolyte imbalances are in sodium and potassium. Electrolyte imbalances are referred to with the prefixes "hypo" (low) and "hyper" (high), combined with the scientific name of the electrolyte.

  • Hyponatremia (low sodium), the most common electrolyte imbalance, is a symptom of kidney disease. It can be caused by other disorders, some medications or when a person drinks too much water without consuming enough salt -- especially during hot weather, when more sweating occurs. The first symptoms are headache, fatigue, weakness and nausea. More severe cases can result in confusion, seizure, coma and death. Low sodium is treated by giving sodium and water intravenously.
  • Hypernatremia (high sodium) can be caused by excessive fluid loss, diabetes, diarrhea, excessive vomiting and some medications. Thirst is typically the first symptom, and many of the other symptoms are the same as low sodium. Older hospitalized patients are particularly susceptible to hypernatremia. Treatment involves slowly replenishing water loss, usually over 48 hours, through drinking or intravenous administration.
  • Hypokalemia (low potassium) is most commonly caused by some diuretics, medicines that help rid the body of excess sodium and water. Other causes include diarrhea, dietary deficiency and excessive sweating. Symptoms include irregular heartbeat, muscle pain, general discomfort or irritability, weakness and paralysis. Treatment can include potassium supplements, foods rich in potassium, or intravenous potassium and water. People who experience hypokalemia because of a diuretic may be given another type of diuretic that doesn't have potassium loss as a side effect.
  • Hyperkalemia (high potassium) is much more serious than hypokalemia. It's usually caused by kidney failure or medications that reduce the amount of potassium excreted by the kidneys. High potassium can cause dangerous changes in the heart's function -- it can even cause the heart to stop. Other symptoms include tingling in the extremities, weakness and numbness. Treatment includes drugs that cause the body to eliminate potassium. In the case of severe or worsening hyperkalemia, treatment must be started immediately.

To learn more about electrolytes and keeping them in balance, follow the links on the next page.