Hypercalcaemia is caused by thiazides.

Understanding the Causes of Hypercalcaemia

Hypercalcaemia is a medical condition characterized by high levels of calcium in the blood. In most cases, two conditions account for 90% of hypercalcaemia cases. The first is primary hyperparathyroidism, which is the most common cause in non-hospitalized patients. The second is malignancy, which is the most common cause in hospitalized patients. Malignancy-related hypercalcaemia may be due to various processes, including PTHrP from the tumor, bone metastases, and myeloma. For this reason, measuring parathyroid hormone levels is crucial when investigating patients with hypercalcaemia.

Other causes of hypercalcaemia include sarcoidosis, tuberculosis, histoplasmosis, vitamin D intoxication, acromegaly, thyrotoxicosis, milk-alkali syndrome, drugs such as thiazides and calcium-containing antacids, dehydration, Addison’s disease, and Paget’s disease of the bone. It is important to note that hypercalcaemia may occur with prolonged immobilization in patients with Paget’s disease of the bone, although this condition is usually normal.

In summary, hypercalcaemia can be caused by various medical conditions, with primary hyperparathyroidism and malignancy being the most common. Measuring parathyroid hormone levels is essential in investigating patients with hypercalcaemia. Other causes of hypercalcaemia include sarcoidosis, tuberculosis, histoplasmosis, vitamin D intoxication, acromegaly, thyrotoxicosis, milk-alkali syndrome, drugs, dehydration, Addison’s disease, and Paget’s disease of the bone.