Dehydration can lead to an imbalance of electrolytes in your bloodstream. Unlike sodium and potassium, which tend to decline with fluid loss, calcium can become too high, leading to hypercalcemia. The amount of calcium, however, doesn’t necessarily change. Instead, the loss of fluids results in higher concentrations of serum calcium. If left untreated, severe hypercalcemia can increase the risk of kidney stones, kidney failure, dementia and arrhythmia.
Mild hypercalcemia is often asymptomatic, so you may never experience symptoms of the condition. As the concentration of blood calcium rises, however, you can develop nausea, vomiting, loss of appetite, constipation, abdominal pain and excessive thirst, which are symptoms shared with dehydration itself. These signs may also be accompanied by fatigue, lethargy, muscle weakness, joint pain and even confusion.
Normally, the excess of calcium triggers the production of calcitonin to help regulate mineral levels in your body. But this thyroid hormone only slows the release of calcium from your bones, so it’s ineffective in reducing the high concentration of this mineral as a result of dehydration. Medical intervention may be necessary to improve hypercalcemia.
Treatment for hypercalcemia relies on the cause of the elevated calcium levels. In this situation, reducing serum calcium involves rehydration. But it isn’t always enough to simply drink water to normalize the fluid level in your body. While most cases of hypercalcemia are relatively mild when caused by dehydration, you may need intravenous fluids to bring calcium levels into a healthy range, and this might require hospitalization.
Preventing hypercalcemia as a result of dehydration revolves around proper hydration techniques. For most people, using your thirst to dictate fluid intake is often sufficient in avoiding dehydration, according to MayoClinic.com. If you’re exercising or ill, however, this may not be an adequate guide. Always drink plenty of fluids before, during and after more strenuous athletic pursuits and increase your fluid intake while you're sick, especially when the illness causes vomiting and diarrhea.