What condition is typically characterized by low serum calcium levels?

Hypoparathyroidism is characterized by low serum calcium levels due to insufficient secretion of parathyroid hormone (PTH). PTH plays a critical role in regulating calcium levels in the blood. In individuals with hypoparathyroidism, the decreased production of PTH leads to a reduced ability of the kidneys to reabsorb calcium, decreased intestinal absorption of calcium, and enhanced bone resorption, all of which contribute to hypocalcemia.

This condition is often associated with symptoms such as muscle cramps, tingling sensations, and in severe cases, tetany (involuntary muscle contraction). The diagnostic lab findings typically include low levels of both serum calcium and PTH, confirming the diagnosis of hypoparathyroidism.

In contrast, other conditions listed do not primarily lead to low serum calcium levels. Hyperparathyroidism, for instance, results in elevated serum calcium due to the excess production of PTH. Hyperthyroidism can impact metabolism but is not directly related to serum calcium levels in the same way. Kidney disease may lead to altered calcium regulation but does not specifically characterize low serum calcium like hypoparathyroidism does.