What are parathyroid glands?

Most people have four parathyroid glands, which are in your neck usually behind the thyroid gland. The parathyroid glands release a hormone called parathyroid hormone (PTH) which maintains a normal blood level of calcium. Optimal levels of calcium are vital for the normal function of the nervous system and skeletal muscles. Adequate calcium is also required for normal blood clotting.

What is hyperparathyroidism?

Sometimes one of the parathyroid glands becomes diseased - growing to an abnormal size and producing too much hormone. This is called hyperparathyroidism, often called PHPT.

What causes hyperparathyroidism?

Parathyroid adenoma: Hyperparathyroidism is most commonly caused by an increase in size and activity of one of the parathyroid glands. This enlarged gland is known as a parathyroid adenoma. The adenoma does not recognise or respond to the blood calcium level and constantly releases high levels of PTH. Often a parathyroid adenoma will be 20 times as large as a normal gland. In a few patients, more than one parathyroid adenoma may be present.

Parathyroid hyperplasia: In this condition, several of the parathyroid glands increase in size and together release large amounts of PTH.

Parathyroid Malignancy: one of the parathyroid glands enlarges and invades the adjacent tissues. This occurs rarely in less than 1% of cases of hyperparathyroidism.

What are the effects of hyperparathyroidism?

  • An increase of calcium in the blood level. If the calcium rises to very high levels you will experience excessive thirst and pass large amounts of urine. Dangerously high levels of blood calcium may occur but this is unusual
  • The high level of PTH will lead to increased release of calcium from the bones resulting in thinning of the bones (osteoporosis) and an increased risk of fractures. In severe cases, bone pain will be present
  • A high level of calcium within the urine can cause kidney stones
  • High blood pressure and stomach ulcers are increased in patients suffering from hyperparathyroidism
  • Some patients with hyperparathyroidism feel tired, depressed, have memory problems, experience frequent headaches, and lack energy. These symptoms are frequently helped if the condition is cured

Some patients experience no symptoms. These symptoms do not necessarily indicate a diseased parathyroid gland.

How is hyperparathyroidism diagnosed?

A specialist consultant may order special blood tests and urine tests to measure the level of calcium in your blood. They may order an MRI or CT scan or an ultrasound to confirm if your parathyroid glands are normal size.

How is hyperparathyroidism treated?

Conservative treatment – mild cases of hyperparathyroidism with only marginal elevation of the blood calcium levels and no damage to the skeleton may be managed by clinic follow-up and regular blood tests. Most patients will be under the care of an endocrinologist. If the calcium level rises or complications develop then the patient will be referred for surgery.

Surgery – patients who have a high calcium level, kidney stones, osteoporosis or symptoms such as lethargy and depression, your consultant may recommend surgical removal (called a parathyroidectomy) of your diseased parathyroid gland.