Medicines for High calcium (hypercalcaemia)

What it is

Hypercalcaemia means a higher-than-normal level of calcium in the blood. Calcium is important for bones, muscles, nerves and many body functions, and its level is normally kept in a tight range, largely controlled by the parathyroid glands and vitamin D. When calcium is raised, it can cause a range of symptoms, often summarised as "bones, stones, groans and moans": bone aches, kidney stones and excessive thirst and urination, tummy upset and constipation, and tiredness, low mood or confusion. Mild hypercalcaemia often causes no symptoms and is picked up incidentally on a blood test. The two most common causes are an overactive parathyroid gland (primary hyperparathyroidism, where one or more of these small glands produces too much parathyroid hormone) and, importantly, some cancers. Other causes include excessive vitamin D or calcium intake, certain medicines, prolonged immobility, and some other conditions. Because the causes range from a common, treatable gland problem to more serious conditions, and because a very high calcium level can itself be dangerous, hypercalcaemia is always assessed to find the cause.

How it is treated

Assessment focuses on confirming the raised calcium and finding the cause, which then guides treatment. A doctor will repeat and confirm the blood test, and arrange further tests — importantly checking the parathyroid hormone level, which helps distinguish an overactive parathyroid (the commonest cause) from other causes, along with vitamin D, kidney function, and, where needed, investigations to look for other causes such as cancer. Treatment depends on the cause and the severity: for primary hyperparathyroidism, mild cases may be monitored while more significant ones are often treated by surgery to remove the overactive gland; where a medicine or excessive vitamin D/calcium is responsible, that is adjusted; and any underlying condition is treated. A very high calcium level, or one causing significant symptoms, is a medical emergency needing urgent hospital treatment — with fluids and specific medicines to bring the level down quickly and protect the kidneys and other organs — alongside treating the cause. Mild, symptom-free hypercalcaemia is investigated and managed less urgently. The reassuring message is that hypercalcaemia is usually identifiable and treatable, most often due to an overactive parathyroid gland, though it is always assessed to find the cause and any very high level is treated urgently.