Which conditions are commonly associated with hypercalcemia?

Hypercalcemia, characterized by elevated calcium levels in the blood, is commonly associated with certain medical conditions, particularly hyperparathyroidism and malignancy.

In hyperparathyroidism, either primary or secondary, there is an overproduction of parathyroid hormone (PTH), which leads to increased calcium reabsorption in the kidneys, enhanced intestinal calcium absorption, and mobilization of calcium from bones. This results in elevated serum calcium levels.

Malignancy can also lead to hypercalcemia through several mechanisms. Some cancers, particularly those that metastasize to bone, can result in increased bone resorption and, thus, elevated calcium levels. Additionally, certain tumors can produce parathyroid hormone-related peptide (PTHrP), mimicking the action of PTH and contributing to hypercalcemia.

In contrast, dehydration, while it can cause elevated calcium levels due to hemoconcentration, is not a primary cause of hypercalcemia. Kidney stones can be a consequence of hypercalcemia rather than a direct cause. Hypothyroidism is generally not associated with high calcium levels and may even be associated with lower calcium levels due to altered bone metabolism. Similarly, vitamin D deficiency typically leads to hypocalcemia, not hypercalcemia, due