Secondary Hyperparathyroidism — what it is and why it matters

If your body keeps raising parathyroid hormone (PTH) because calcium and phosphate are out of balance, that’s secondary hyperparathyroidism. It’s most common in people with chronic kidney disease (CKD), but vitamin D deficiency and malabsorption can cause it too. Left unchecked, it can weaken bones, cause itching, and change calcium levels in ways that can harm your heart and blood vessels.

What causes it?

The parathyroid glands respond to low calcium or high phosphate by making more PTH. In CKD, the kidneys can’t clear phosphate well and make less active vitamin D. That combination lowers calcium levels in the blood and keeps PTH high. Other causes include long-term vitamin D deficiency, certain gut problems that block vitamin D absorption, and some rare genetic conditions.

Classic lab patterns include high PTH, often with low or normal calcium and high phosphate. Your doctor will also check vitamin D levels and kidney function. If you have CKD, tests are repeated regularly to watch trends rather than single numbers.

How it’s treated

Treatment aims to lower PTH while keeping calcium and phosphate in a safe range. Common steps are simple but need follow-up:

• Fix vitamin D: Give cholecalciferol (vitamin D3) or active forms like calcitriol if the kidneys can’t activate vitamin D. This lowers PTH for many people.
• Limit phosphate: Cut back on high-phosphate foods (processed foods, cola drinks, some dairy and meat concentrates). Your doctor may add a phosphate binder — a pill you take with meals that blocks phosphate absorption.
• Calcimimetics: Drugs such as cinacalcet trick the parathyroid into making less PTH. They work well if vitamin D and binders aren’t enough, but they can lower calcium too, so labs must be checked.
• Surgery: Parathyroidectomy (removing part or most of the parathyroid tissue) is an option when medical therapy fails or PTH levels are very high and causing symptoms or bone disease.

Doctors tailor treatment based on kidney function, calcium and phosphorus levels, symptoms, and bone health. If you’re on treatment, expect blood checks every few weeks to months at first, then less often once things stabilize.

Practical tips you can use today: carry a list of your lab trends, ask how often to check PTH/calcium/phosphorus, take phosphate binders exactly with meals, and tell your doctor about any muscle pain, bone pain, itching, or weakness — these can be signs PTH or calcium are off.

If you have CKD or persistent low vitamin D, mention secondary hyperparathyroidism to your clinician. Early action prevents bone damage and reduces risks tied to long-term mineral imbalance.