The parathyroid glands are four glands that sit on the back of the thyroid gland. The tiny, rice-sized glands are responsible for producing parathyroid hormone (PTH) that helps regulate calcium in the bloodstream and tissues that require it.
Calcium is important for bone strength, brain activity and muscle function. When the parathyroid glands are functioning properly, they balance the amount of calcium that is released into the bloodstream. However, when the system is not in balance and calcium levels become too high or too low, it can lead to health complications.
When the parathyroid gland(s) manufacture an excessive amount of PTH, the overabundance of the hormone causes calcium levels to rise. This condition is known as hyperparathyroidism. Hyperparathyroidism can be primary or secondary.
Primary hyperparathyroidism occurs when one or more of the parathyroid glands become enlarged and begins producing too much PTH. This causes calcium levels to rise and increases the risk of stroke or other health issues. This is often triggered by a non-cancerous (benign) adenoma (tumor) on the parathyroid. Cancerous parathyroid tumors are uncommon.
Secondary hyperparathyroidism is much rarer and occurs when another health condition, such as kidney failure with dialysis, stimulates the parathyroid gland causing it to overproduce. It typically occurs when blood calcium levels are low, triggering the parathyroid glands to overproduce.
Symptoms of hyperparathyroidism
Hyperparathyroidism can occur with no symptoms at all. When symptoms are present, they include:
- Kidney stones
- Tingling of the hands and feet
- Confusion or depression
- Weak bones prone to fracture
- Loss of appetite or nausea
- Abdominal pain
Diagnosis of hyperparathyroidism
Blood tests to confirm that PTH and calcium levels are high is the first step in diagnosing parathyroid disease. If both levels are elevated, one or more of the parathyroid glands is likely enlarged.
Other tests may be needed to identify secondary conditions.
Treatment of hyperparathyroidism
Treatment of hyperparathyroidism includes specific medications (calcimimetics) that work to lower calcium levels by mimicking calcium in the blood. Hormone replacement therapy may be beneficial for post-menopausal women who suffer from osteoporosis. Bisphosphonate drugs are sometimes prescribed to halt calcium loss in the bones.
Surgical removal of the enlarged parathyroid gland(s) may be necessary to control calcium levels if medications are not effective. Removal is not a reason for concern since individuals can function normally with the remaining glands.
If the parathyroid glands are not making enough PTH, it causes a condition known as hypoparathyroidism. This results in low blood calcium levels and high blood phosphorus levels. This occurs as a result of certain genetic or endocrine disorders or when the parathyroid glands have sustained injury. The condition is treated with supplements to restore calcium/phosphorus balance.