What is Hyperparathyroidism?
Hyperparathyroidism is a condition where there is an imbalance in blood calcium levels and parathyroid hormone (PTH). The diagnosis is based on blood tests (imbalanced Calcium and PTH), but typically also requires testing phosphorus, kidney function, and vitamin D levels as these can also affect calcium and PTH balance. “Primary Hyperparathyroidism” is diagnosed when the parathyroids are thought to be the source of the problem. “Secondary Hyperparathyroidism” is diagnosed when the parathyroids oversecrete PTH in reaction to another imbalance (e.g., low vitamin D or chronic kidney disease).
What (and where) are the parathyroid glands?
The parathyroid glands are several small glands that are part of the endocrine system. They sit behind the thyroid gland in the lower neck. There are normally 2 glands on each side – 4 total – and each gland is typically only a little larger than a grain of rice. The parathyroid glands secrete a hormone (protein that travels through the blood to affect other organs) called Parathyroid Hormone (PTH) that affects how calcium is processed throughout the body. Excess PTH most commonly comes from a single benign parathyroid growth (adenoma), but may also result from overgrowth of all four glands (known as multigland disease or hyperplasia).
Why is calcium balance important?
Maintaining a normal calcium level is important for various functions of the human body. Our bones serve as the main storage of calcium in the body and our parathyroid glands adjust PTH levels every few minutes to keep our blood calcium level in a very specific range by directing processing of calcium in the bones, kidneys and intestines. Imbalances in calcium and PTH levels can cause damage to the stomach, kidneys, bones, heart and blood vessels.
What are the symptoms of hyperparathyroidism?
Often times, people with elevated calcium levels do not have any symptoms. The diagnosis may be made by elevated calcium and parathyroid levels found on routine blood work.
The symptoms of hyperparathyroidism usually reflect the effects of excess parathyroid hormone (PTH) raising the levels of calcium in the bloodstream. The higher blood calcium can then:
- Increase stomach acid – causing irritation of the stomach and intestines (including ulcers and heartburn)
- Increase calcium filtration by the kidneys (increased urine calcium can lead to kidney stones and bladder irritation).
- Deplete calcium from the bones – leading to early bone loss (osteopenia and osteoporosis) and risk for fractures.
- Affect the muscles and nerves – causing joint and muscle pains.
- Cause imbalances in brain functions – causing memory problems, depression or anxiety, fatigue, difficulty concentrating, and sleep problems.
What is “variant” primary hyperparathyroidism?
In “traditional” primary hyperparathyroidism, both the calcium and PTH levels are elevated. We now recognize additional imbalances between calcium and PTH. Some patients have a normal calcium with elevated PTH (“normocalcemic or eucalcemic variant”), elevated calcium with normal PTH levels (“normohormonal variant”) and high normal calcium/PTH (“early” or “inappropriately normal” variant”).
Currently, the recommendations for surgery are the same as for patients “traditional” primary hyperparathyroidism; however, the long term benefits of surgery are unclear. Based on our experience at DCES with “variant” parathyroid disease, we have noticed several trends: 1. “Variants” now account for 1/3 to 1/2 of our patients. 2. There is a higher rate of hyperplasia (all parathyroids enlarged/overactive requiring removal of multiple glands). 3. There is a lower “cure” rate and higher rate of recurrent hyperparathyroidism – meaning that it may come back with time in the remaining gland(s).
What other testing is typically recommended?
A 24-hour urine collection test can help determine the amount of calcium filtration in the kidneys, determine risk for kidney stones, and can also screen for genetic causes of calcium-PTH imbalance that are not improved by parathyroid surgery. A DEXA scan (bone mineral density scan) is also recommended to detect bone loss. Kidney function and vitamin D levels can determine if the parathyroid disease is “Primary” or “Secondary” (or occasionally both). These tests help determine if/when surgery may be helpful and may affect pre- and postoperative recommendations.
What are the options for treatment of hyperparathyroidism?
- Surgery is generally recommended for patients that have evidence of on-going bone loss, kidney stones and/or severe symptoms.
- Surgery does not always improve symptoms, especially in patients with mild/variant disease.
- Observation may also be considered for patients with mild disease or other health problems.
- Additionally, there are some medical therapies available to block calcium receptors or to treat bone loss. Your doctor can discuss your options with you.
What about imaging for hyperparathyroidism?
Parathyroids, even enlarged ones, can be difficult to find on medical imaging. Therefore, the diagnosis and treatment plan are usally dependent on blood work and discussion with your doctor or surgeon. Most surgeons use medical imaging to help plan surgery, once the decision for surgery has already been made. Your surgeon, insurance coverage and local imaging options may determine what type(s) of imaging may be ordered for surgical planning.