Tertiary hyperparathyroidism occurs when the parathyroid glands work in overdrive on their own after a prolonged period of secondary hyperparathyroidism, regardless of treatment. In tertiary hyperparathyroidism, the parathyroid glands have been overstimulated for so long that they continue to make too much hormone even if the underlying trigger has been treated.

What is tertiary hyperparathyroidism?

Tertiary hyperparathyroidism is a condition that develops as a progression of secondary hyperparathyroidism. Secondary hyperparathyroidism is when all four of the parathyroid glands make too much parathyroid hormone as an appropriate response to some other underlying health issue. Tertiary hyperparathyroidism can occur after a prolonged period of secondary hyperparathyroidism, regardless of treatment. The parathyroid glands begin to function on their own, causing a high calcium and high parathyroid hormone.

What are the symptoms of tertiary hyperparathyroidism?

Each person may experience symptoms differently. Symptoms of too much calcium in the blood may include:

• Constipation
• Nausea/vomiting
• Increased thirst
• Joint pain
• Muscle weakness
• Kidney stones or kidney pain
• Frequent urination
• Lack of energy and extreme tiredness (fatigue)
• Loss of appetite
• Loss of bone mineral density

Other serious symptoms may include:

• Depression
• Memory loss
• Trouble concentrating
• Trouble sleeping

A high calcium with severely high parathyroid hormone level might need to be addressed with surgery before receiving a new kidney, as it may put you at risk of losing your kidney graft. The symptoms of tertiary hyperparathyroidism may look like other health problems. Always talk with your healthcare provider for a diagnosis.

How do the parathyroid glands work?

The parathyroid glands are small glands that sit behind the thyroid in the center of the neck. Occasionally, one or more parathyroid glands may be in an unusual location in the neck or upper chest region. Most people have four parathyroid glands, but in rare cases there may be a fifth or sixth gland.

Your parathyroid glands make parathyroid hormone to keep blood calcium levels within the normal range. Parathyroid hormone:

• Releases calcium from bones
• Reabsorbs calcium from the kidney
• Increases how much calcium is absorbed from food.

What causes tertiary hyperparathyroidism?

In some cases, no cause can be found. The most common causes of tertiary hyperparathyroidism are vitamin D deficiency, malabsorptive syndromes (such as celiac disease or gastric bypass) and progressive kidney failure.

When all the parathyroid glands are making excess parathyroid hormone, they all enlarge, and this is called parathyroid hyperplasia. This condition is noncancerous.

Parathyroid hyperplasia fuels hyperparathyroidism: the enlarged parathyroid glands ignore the body’s typical control mechanism and continue to produce too much parathyroid hormone, resulting in a high calcium.

How is tertiary hyperparathyroidism diagnosed?

The condition may not have any symptoms or complications. Sometimes this problem is found during a routine blood test as part of a physical exam.

You'll likely have additional blood tests done to check the levels of calcium, parathyroid hormone, vitamin D, creatinine and phosphorous. Your healthcare provider may also request other testing:

• CT scan
• Ultrasound study of your neck, to find enlarged parathyroid glands
• Dual energy X-ray absorptiometry (DXA scan), to determine bone density and reveal any loss of bone tissue.

Testing can also help decide if surgery may be needed.

How is tertiary hyperparathyroidism treated?

Treatment will depend on the cause of your hyperparathyroidism. It will also depend on how severe the condition is.

• Treatment usually includes surgery and treating the underlying cause.
• Surgery to remove the affected glands may be needed. This usually means removing 3.5 of the 4 parathyroid glands.

Medically reviewed by Aarti Mathur, M.D., Ph.D., July 17, 2026