The 4 parathyroid glands are located on the back of the thyroid gland. They are tiny, each one normally measuring around 5mm in size. Despite their small size they perform a vital role. They control the amount of calcium in the bloodstream. Our bodies need a stable calcium level so that nerves and muscles can work normally. Too little calcium in the bloodstream can cause muscles to go into spasm and nerves to stop working, a condition called Tetany.
The parathyroids make parathyroid hormone (PTH). PTH travels around the body in the blood and works to increase the amount of calcium. It does this by acting mainly in 3 ways 1) by dissolving calcium from the bones, 2) by reabsorbing calcium in the kidneys from the urine and 3) by acting with Vitamin D to increase the amount of dietary calcium we take up from our gut.
Another important factor in Calcium maintenance is Vitamin D. This is absorbed from our diet and converted to its active form by the action of UV light on our skin. It then is activated by PTH and helps to increase calcium absorption from the gut.
There are 3 main parathyroid problems that we see in our practice:
Hyperparathyroidism (overactivity of one or more parathyroid glands)
Hypoparathyroidism (underactivity of the parathyroids which mainly occurs as a complication of total thyroidectomy)
Parathyroid Carcinoma (a rare tumour)
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