Ask the Doctors: Hyperparathyroidism can cause kidney stones; what you need to know

Dear Doctors: I’ve suffered from kidney stones since 2017. A parathyroid test came back high, as did my serum calcium. An endocrinologist ruled out a malignancy and confirmed the diagnosis of hyperparathyroidism. What is it, and what can I expect?

Answer: Hyperparathyroidism occurs when the parathyroid glands become overactive.

These are four tiny glands about the size of a grain of rice that help manage the balance of calcium and phosphate in the blood needed to maintain bone health and for coordinated muscle movement.

The parathyroid glands are at the base of your throat, just behind the thyroid. They share real estate and part of their name with the thyroid gland, but their functions aren’t related.

When calcium levels in the blood fall too low, it prompts the parathyroid glands to produce parathyroid hormone, PTH. This results in stored calcium in the bones being released into the blood.

As blood levels of calcium reach optimal levels, the release of PTH stops.

With hyperparathyroidism, the parathyroid glands continue to release PTH. Blood levels of calcium become too high, which leads to complications, including kidney stones, osteoporosis, abdominal pain, nausea and vomiting, constipation, excessive urination, cognitive problems, pain in the bones and joints and loss of stamina.

Risk factors include being a post-menopausal woman, prolonged or severe vitamin D deficiency and radiation treatment to the neck.

There are two classifications for hyperparathyroidism — primary and secondary. Primary means something is directly affecting the gland. Secondary hyperparathyroidism, which is rare, occurs when other conditions have a spillover effect, most often due to kidney failure or severe vitamin D deficiency.

The most common cause of hyperparathyroidism is an adenoma, a noncancerous growth. Mild cases of hyperparathyroidism can call for watchful waiting. When the condition causes significant side effects, surgery is needed.

That’s often an outpatient procedure. In about one-third of cases, more than one parathyroid gland needs to be removed.

Once the malfunctioning glands are removed, the person is considered cured. The remaining healthy parathyroid glands will take over the work of keeping calcium and phosphate levels in balance.

People typically return to normal activities one to two weeks after surgery. The main complaints are fatigue and sore throat, usually gone within a week or two.

It’s common for calcium and PTH levels to be checked six to eight weeks following the surgery, and then on a yearly basis. It’s also possible that your healthcare provider will ask you to have an annual bone-density test.

Dr. Eve Glazier and Dr. Elizabeth Ko are internists on the faculty at UCLA Health.