Parathyroid glands: what they do and when to worry

The parathyroid glands are four tiny glands behind your thyroid. They make parathyroid hormone (PTH), the main control for blood calcium. Calcium affects bones, nerves, muscles and your heartbeat, so the parathyroids have a big job despite their small size.

When the parathyroid acts up

Too much PTH (primary hyperparathyroidism) raises blood calcium. That can cause kidney stones, bone pain or loss, stomach upset, fatigue, and mood changes. People sometimes say "stones, bones, groans and psychiatric overtones"—that’s an old way to list the common signs. Causes often include a single adenoma (a benign growth) or gland overactivity.

Too little PTH (hypoparathyroidism) lowers blood calcium and brings numbness, tingling around the mouth, muscle cramps, and in severe cases, muscle spasms or breathing trouble. The usual causes are surgery on the thyroid or parathyroids, autoimmune disease, or rarely genetic conditions.

How doctors check parathyroid health

Start with blood tests: total or ionized calcium, PTH, phosphate and vitamin D. High calcium with high or inappropriately normal PTH suggests primary hyperparathyroidism. Low calcium with low PTH points to hypoparathyroidism. Your doctor may also check 24-hour urine calcium to see if kidneys are spilling calcium.

Imaging helps find a bad gland before surgery. Common scans include neck ultrasound and a sestamibi scan. If those don’t find anything, more advanced imaging like 4D CT or MRI may be used at specialty centers.

Treatment depends on the problem. For symptomatic primary hyperparathyroidism, surgery to remove the abnormal gland (parathyroidectomy) is the usual cure. If surgery isn’t an option, medicines like cinacalcet can lower calcium, and bone-protecting drugs may be used to protect bones. For hypoparathyroidism, doctors treat with oral calcium and active vitamin D (calcitriol); in select cases, PTH replacement therapy is available under specialist care.

Simple, practical steps matter. Drink enough water to reduce stone risk if your calcium is high. Don’t start high-dose vitamin D or calcium supplements without lab checks—those can make high-calcium problems worse. If you have low calcium, follow dosing instructions closely and get frequent blood checks until levels are stable.

Ask your provider about a DEXA bone scan if you have long-standing parathyroid disease—bones can weaken even if you don’t feel pain. Keep a list of symptoms that change—new kidney pain, worsening fatigue, muscle twitching, or mood swings—and call your clinician when they appear.

Many parathyroid issues are treatable. With the right tests and a clear plan—surgery, medication, or regular monitoring—you can manage calcium and protect your bones and kidneys. If you’re unsure, a referral to an endocrinologist or an experienced surgeon is a good next step.