What is Hyperparathyroidism?

This is a state where the parathyroid glands are secreting excessive amounts of parathyroid hormone. This can occur for a number of reasons and is variable in the symptoms it produces, from none at all to the characteristic features of hypercalcaemia (discussed in the 'symptoms' section).

The causes of hyperparathyroidism can be divided into three:

• Primary cause - this is the most common, where the abnormality lies within the parathyroids themselves
• Secondary cause - this is where parathyroid hormone (PTH) levels are raised due to any disease process which causes low calcium levels
• Tertiary cause - a rare situation in secondary hyperparathyroidism where usually one of the parathyroids becomes autonomous and secretes excess PTH even when the calcium levels have returned to normal.