What can excessive levels of calcium lead to in severe cases?

Excessive levels of calcium in the body can lead to various physiological complications, and in severe cases, one of the most critical consequences is cardiac arrest. This occurs because high calcium levels can disrupt the normal electrical activity of the heart. Calcium plays a vital role in the contraction of heart muscles and the generation of electrical impulses that regulate heartbeat. When calcium levels become excessively elevated, it can lead to arrhythmias, or irregular heart rhythms, which may progress to a complete halt of the heart's pumping action, resulting in cardiac arrest.

Other potential complications of hypercalcemia can include muscle spasms and weakness due to the effects on neuromuscular function, but these are generally not as acute or life-threatening as the risk of cardiac arrest. Severe dehydration and hypotension typically relate to fluid balance rather than direct consequences of hypercalcemia, making them less relevant in this context.