Primary hyperparathyroidism occurs when the parathyroid glands produce too much parathyroid hormone (PTH). This can lead to health complications.

Primary hyperparathyroidism is a relatively common health issue that someone may not know they have until complications arise. It stems from issues within the parathyroid glands in the neck, causing them to secrete excessive amounts of PTH. Often, it is due to a benign tumor.

PTH is responsible for regulating calcium levels in the body. If PTH levels become elevated, calcium levels in the blood increase, leading to problems such as bone thinning and kidney stones.

Doctors can treat primary hyperparathyroidism by removing the parathyroid glands or with medication to lower PTH production.

This article looks at primary hyperparathyroidism, including its causes, diagnosis, and treatment.

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Overactivity of the parathyroid glands characterizes primary hyperparathyroidism. “Primary” means the issue begins in the parathyroid glands rather than being secondary to another health problem, such as kidney failure.

Four pea-sized parathyroid glands develop in the neck, behind the thyroid gland. These glands regulate the calcium levels in the body by producing parathyroid hormones. When one or more of the glands become overactive and secrete too much PTH, it disrupts the calcium balance in the bloodstream, leading to various health problems.

The most common cause of primary hyperparathyroidism is the development of a benign tumor on one of the parathyroid glands. This is known as parathyroid adenoma.

Less commonly, hyperplasia (or enlargement) of multiple parathyroid glands causes it. Parathyroid cancer can also be a cause, though it is rare for it to be the underlying reason.

While the exact reasons for these gland issues are not always clear, genetic factors and certain medical conditions may play a role in their development.

Primary hyperparathyroidism results from a problem within the parathyroid glands themselves.

In contrast, secondary hyperparathyroidism occurs as a response to external factors that disrupt calcium balance. These external factors may include:

  • kidney disease
  • vitamin D deficiency
  • calcium deficiency

While both conditions elevate PTH levels, their underlying causes and treatment approaches differ.

The symptoms of primary hyperparathyroidism can vary widely, and some people may not experience any noticeable symptoms.

Common symptoms include:

Without treatment, primary hyperparathyroidism can lead to more severe complications over time, such as osteoporosis and fractures.

Furthermore, almost 1 in 4 people with persistent high calcium levels have some degree of mental health complications, including:

Diagnosis usually starts with blood tests to measure calcium and PTH levels. If levels of both are high, it could indicate primary hyperparathyroidism.

Doctors may also order imaging to identify the exact location of the atypical parathyroid glands. Ultrasound and CT scans are usually the standard tests.

Bone density scans, which are also known as dual-energy X-ray absorptiometry scans, may also be helpful alongside other tests. These scans evaluate the density and strength of the bones, providing valuable information about the impact of elevated calcium levels on bone health.

When an individual has symptoms, the treatment for primary hyperparathyroidism often involves surgery to remove the affected parathyroid glands. The procedure is called a parathyroidectomy.

Surgery may be an option for people with asymptomatic — referring to no symptoms — primary hyperparathyroidism. Guidelines recommend surgery in this case when the person:

  • is younger than 50 years
  • has a blood serum calcium level of more than 1 milligram per deciliter above the typical upper limit
  • shows osteoporosis on bone scan
  • has a history of bone fractures
  • shows evidence of kidney or urinary stones

For older people and those with mild hypercalcemia and no significant complications, doctors may adopt a “watch and wait” approach.

Nonsurgical approach

Doctors may prescribe bisphosphonates or cinacalcet if a person has very high calcium levels. These medications help decrease the amount of PTH the parathyroid glands make and lower calcium levels in the blood.

Pamidronate (Aredia) and zoledronic acid (Zometa) are two types of bisphosphonates that doctors use to lower dangerously high calcium levels in the hospital.

Doctors may prescribe cinacalcet to lower chronically elevated calcium levels in people who cannot have surgery. If the person also has osteoporosis, they will also need a bisphosphonate such as alendronate.

As chronic vitamin D deficiency is a risk factor for hyperparathyroidism, doctors may also recommend vitamin D supplements starting at 1,000 International Units daily.

This may depend on when people receive a diagnosis. That said, doctors diagnose most people with primary hyperparathyroidism while they are asymptomatic. Elevated calcium levels may be an incidental finding during routine assessments. At this stage, they are not typically severe enough to cause noticeable problems or symptoms.

With early diagnosis and appropriate treatment, the outlook for individuals with primary hyperparathyroidism is generally positive.

Surgical parathyroidectomy can permanently cure the issue, and bone mineral density improves over time. However, there is an increased risk of heart problems, and experts are unsure if this improves after treatment or surgery.

Primary hyperparathyroidism arises from the overactivity of the parathyroid glands, which secrete excessive parathyroid hormone (PTH). Often, the cause is a benign tumor on the glands.

The excess PTH disrupts calcium balance in the body and can cause complications such as kidney stones, heart problems, and loss of bone density. Symptoms can vary but may include fatigue, bone pain, and frequent urination.

Doctors diagnose primary hyperparathyroidism through blood tests. If a person has symptoms or meets certain other criteria, doctors may recommend surgical removal of the atypical gland. Surgery can cure the condition, and bone loss returns to typical levels.