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The Parathyroid Glands are 4 tiny glands (the size of a grain of rice) located on the back of the Thyroid Gland. These glands produce a hormone called parathyroid hormone (PTH), which regulates the level of calcium in your blood stream.

Parathyroid hormone controls the amount of calcium in your bloodstream by regulating the amount of calcium that you absorb from your diet, regulating the amount of calcium that you excrete in your urine and regulating the amount of calcium that goes in and out of your bones.

The role of Calcium in the human body

Calcium is essential to life and is used throughout the body for three main purposes:

  1. To assist with nerve transmission to ensure normal electrical impulses within the nervous system. This explains why having a high calcium level can result in symptoms related to the nervous system (anxiety, depression, weakness, tiredness, poor concentration).
  2. To provide electrical conductivity for muscle fibres throughout the body. This explains why having a high calcium level can sometimes result in a feeling of weakness and muscle cramps.
  3. Calcium is an integral part of the skeletal system. There is a constant state of flux of calcium going in and out of bones. The Parathyroid glands help regulate bone absorption and resorption of calcium to ensure that the bones are kept as strong as possible.


Hyperparathyroidism occurs when one (or more) of the four parathyroid glands becomes overactive. This results in inappropriately high amounts of PTH being produced which leads to inappropriate elevation of your blood calcium level.

The most common cause of Hyperparathyroidism is enlargement of one Parathyroid gland by a benign tumour called a Parathyroid Adenoma.

What are the symptoms of Hyperparathyroidism?

  • Chronic fatigue
  • Poor concentration
  • Tendency towards anxiety or depression
  • Generalised non-specific aches and pains
  • Sleep disturbance
  • Irritability
  • Forgetfulness
  • Gastric reflux/heartburn
  • Kidney stones
  • High blood pressure
  • Occasionally recurrent headaches

Hyperparathyroidism is a diagnosis made by testing the level of calcium and PTH in your bloodstream.

Once a diagnosis of Hyperparathyroidism is made X-ray investigations are used to try and locate the offending problem parathyroid gland/s. Investigations include one or more of the following:

  • Ultrasound scan
  • Parathyroid Sestamibi scan
  • 4D CT scan

For more information about hyperparathyroidism: