Parathyroid hyperplasia refers to the enlargement of the four parathyroid glands. Parathyroid hyperplasia causes about 15% of cases of hyperparathyroidism, which leads to high levels of calcium in the blood (hypercalcemia). The average parathormone level ranges from 10 to 65 pg/ml. If a person's parathormone level rises above this range, it can be said to be hyperparathyroidism.

The parathyroid glands are four glands located behind the thyroid gland in the neck. These glands secrete parathormone. Parathormone maintains blood calcium balance. It also plays a role in vitamin D level and phosphate balance.

Parathyroid hyperplasia refers to the enlargement of the four parathyroid glands. Parathyroid hyperplasia causes about 15% of cases of hyperparathyroidism, which leads to high levels of calcium in the blood (hypercalcemia). The average parathormone level ranges from 10 to 65 pg/ml. If a person’s parathormone level rises above this range, it can be said to be hyperparathyroidism.

Parathyroid hyperplasia can occur randomly or inherited. Patients with parathyroid hyperplasia often have symptoms of hyperparathyroidism. These patients may experience lethargy, nausea, constipation, muscle pain, kidney stones, bone fractures and osteoporosis. In advanced cases, parathyroid hyperplasia should be treated early so that kidney stones and bone problems do not cause irreversible consequences.



Since parathyroid hyperplasia may be a part of some hereditary syndrome groups and cancer diseases are also present in this syndrome family, the disease risk should be calculated more broadly. Other diseases may also need to be investigated.

There is also the possibility of later development of parathyroid adenoma in glands with parathyroid hyperplasia.

Possible causes of parathyroid hyperplasia:

  • Radiation
  • Hereditary diseases
  • Long-term use of Lithium
  • Kidney failure

Diagnosis of parathyroid hyperplasia

In patients with parathyroid hyperplasia, low serum phosphorus, high parathormone level, high serum chloride level, low serum bicarbonate level, and high calcium excretion in the urine can be seen together with high serum calcium level. Low bone mineral density can be detected in patients undergoing bone examination.

In patients who are thought to have a parathyroid-related problem, a definitive diagnosis is made by neck ultrasonography, scintigraphy, computed tomography or magnetic resonance imaging methods, following the evaluation of blood and urine tests. Sometimes a biopsy may also be required.

Since parathyroid hyperplasia may cause similar appearance and clinical conditions with parathyroid adenoma or parathyroid cancers, the definitive diagnosis is made by histopathological evaluation by taking a biopsy. It should also be noted that some hyperplasia or adenoma conditions can transform into each other.



In parathyroid hyperplasia, all glands are usually involved. Rarely, a few may have hyperplasia. In parathyroid hyperplasia, hyperplasia of the chief cells of the parathyroid is usually seen, while hyperplasia of the clear cells can rarely be seen. Adipose tissue is rare in parathyroid hyperplasia tissue.

In hyperplasia of clear cells in the parathyroid glands, the parathyroid glands can grow up to 100 g. Generally, the upper glands are larger than the lower glands. In fact, these two glands can grow to touch each other, giving the appearance of a single giant gland. There is excessive enlargement of the parathyroid glands and primary piherparathyroidism is seen in these patients.

Treatment of parathyroid hyperplasia

The treatment of parathyroid hyperplasia is surgery. Usually, almost all four glands are removed. Surgical treatment alternatives may vary depending on the patient’s clinic and the level of hyperplasia in the parathyroid glands. A small piece is implanted in the forearm to restore the body’s calcium balance. However, if hypercalcemia recurs in the future, this part will be easily accessible surgically and may need to be removed.

Complications of parathyroid hyperplasia treatment

Parathyroid hyperplasia surgery Complications of the treatment are the complications of the surgical procedure. Treatment is mostly successful and resolves quickly. Although very rare, hoarseness or neurological symptoms due to nerve cuts may occur. In addition, bleeding and rarely hypothyroidism may develop.