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Dehydration & Potassium Levels

Dehydration occurs when the body lacks enough water to continue its metabolic processes. Water is an essential compound for the body’s many biochemical reactions. It is used during energy production and excretion of toxic materials. When the body cannot keep up with its fluid needs, dehydration ensues. Dehydration can then affect many cellular processes in the body. One effect of dehydration is on the potassium level in the blood.

The Facts

Potassium is an important electrolyte in your body. Electrolytes are electrically charged molecules important for fluid balance and waste removal. Potassium is also important in maintaining a regular heart rhythm. Most potassium exists inside the body’s cells, so changes in the level of potassium in the blood stream can cause serious health effects.

Symptoms of Dehydration

Dehydration and Sodium Levels

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Initial symptoms of dehydration include dry lips and mouth, dry skin, increased heart rate and decreased urine output. If the dehydration worsens, the heart rate increases more and blood pressure can fall, resulting in light-headedness, dizziness and loss of consciousness. In severe dehydration, shock and brain, liver and kidney damage can result.


There are many causes of dehydration, but essentially a person becomes dehydrated if they lose too much fluid or become unable to ingest enough water. The elderly can become dehydrated because they can’t recognize how much fluid they are losing, according to the Merck Manuals. Infants become dehydrated because the amount of fluid they lose represents a larger proportion of their bodily fluids when compared to that of older children and adult experiencing dehydration. In the most common form of dehydration, electrolytes such as potassium are lost, resulting in decreased levels in the blood stream.


Electrolyte Imbalance in Infants

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Common causes of dehydration include excessive sweating, vomiting and diarrhea. All these can result in hypokalemia, or low potassium levels. Diabetic ketoacidosis, in which a person with diabetes cannot use sugar as energy source and resorts to the use of fats to satisfy its energy requirements, can also result in low potassium levels, or can cause hyperkalemia, abnormally high level of potassium.


Hypokalemia can result in muscle weakness and cramps, and even paralysis. According to the Merck Manuals, since potassium is important for preserving a normal heart rhythm, hypokalemia and hyperkalemia can both cause abnormalities called arrhythmias. In particular, a high potassium level can result in a life-threatening arrhythmia called ventricular fibrillation, which impairs the heart’s ability to pump blood to the tissues.