Hyperparathyroidism can cause kidney stones


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

Dear Reader: Hyperparathyroidism occurs when the parathyroid glands become overactive. These are four tiny glands, each one about the size of a grain of rice. They help manage the specific balance of calcium and phosphate in the blood needed to maintain bone health and for coordinated muscle movement. The parathyroid glands are located at the base of your throat, just behind the thyroid. Although they share real estate and part of their name with the thyroid gland, their functions are not related.

When calcium levels in the blood become too low, it prompts the parathyroid glands to produce parathyroid hormone, or PTH. This results in stored calcium in the bones being released into the blood. As blood serum levels of calcium reach optimal levels, the release of PTH stops. When someone has hyperparathyroidism, the parathyroid glands ignore the “stop” command and continue to release PTH. Blood levels of calcium become too high, which leads to complications, including the kidney stones you’ve been having. Other ill effects can include osteoporosis, abdominal pain, nausea and vomiting, constipation, excessive urination, cognitive problems, pain in the bones and joints, and loss of stamina. Risk factors for the condition 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 that something is directly affecting the gland itself. Secondary hyperparathyroidism, which is rare, occurs when other conditions have a spillover effect. This is most often due to kidney failure or severe vitamin D deficiency.

The most common cause of hyperparathyroidism is an adenoma, which is a noncancerous growth that can occur in glandular tissues. Mild cases of hyperparathyroidism can call for watchful waiting. But when the condition causes significant side effects, surgery is needed.

Elizabeth Ko, MD and Eve Glazier, MD

Surgery for primary hyperparathyroidism is often an outpatient procedure. The surgeon will order scans for a clearer understanding of the problem. In about one-third of cases, it turns out that more than one parathyroid gland needs to be removed. For that reason, the surgeon will examine all four glands during the procedure. Once the malfunctioning glands are removed, the person is considered to be cured. The remaining healthy parathyroid glands will take over the work of keeping calcium and phosphate levels in proper balance.

Possible surgical complications include vocal cord damage and chronic low calcium levels, but neither of these are common. Patients can return to normal activities one to two weeks after surgery. The main complaints are fatigue and sore throat, which usually go away 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 health care provider will ask you to have an annual bone density test.

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