What is hypoparathyroidism?
Hypoparathyroidism is a rare, complex condition in which your parathyroid glands are either absent or damaged. As a result, your body cannot produce sufficient amounts of parathyroid hormone, also known as PTH.
PTH plays a central role in regulating the calcium and phosphorus in your body, so people with hypoparathyroidism are at risk for hypocalcemia (low blood calcium), hyperphosphatemia (high blood phosphate), and other chemical imbalances.
What causes hypoparathyroidism?
The parathyroid glands may slow or stop PTH production for several reasons:
Surgery is the most common cause of acquired hypoparathyroidism. People who have had surgery for thyroid cancer, for benign growths (adenomas) on the thyroid or parathyroid, or for other types of head or neck cancer, are at risk for parathyroid damage. Hypoparathyroidism after surgery may be transient or permanent. Doctors normally monitor and manage low calcium levels after surgery until parathyroid function returns to normal. Chronic hypoparathyroidism is typically determined if the gland function has not returned 6 months after surgery.
Autoimmune is the second most common form of hypoparathyroidism in adults. It may occur alone or as part of autoimmune polyglandular syndrome (APS), a condition involving multiple autoimmune disorders associated with the endocrine glands.
Hereditary, or familial hypoparathyroidism occurs when the parathyroid glands either aren’t present or don’t work properly at birth.
Radiation treatment for cancer in your head or neck region—or radioactive iodine treatment for hyperthyroidism—can damage the parathyroid glands. However, this is a very rare complication.
Idiopathic is the term doctors use when the cause is not known.
What are the symptoms of hypoparathyroidism?
Having the right amount of calcium in your blood is essential to proper functioning of many parts of the body: the heart, nervous system, kidneys, bones and teeth. A person with hypoparathyroidism who has hypocalcemia (low blood calcium) may experience a variety of symptoms, including:
- Tingling or burning in lips, fingers, feet, and toes
- Facial numbness or twitching
- Muscle spasms, twitching, cramping
Cognitive and emotional symptoms:
- Personality changes
- Memory problems
Complications can occur due to low blood calcium and/or from too much calcium being deposited in other tissues. Some people may experience severe, possibly life-threatening complications, including seizures, kidney stones or kidney disease, heart rhythm disturbances, and abnormal bone formation, which can make the bones more prone to fracture.
How is hypoparathyroidism diagnosed?
Your doctor will begin by asking for your medical history, including symptoms, past neck surgery, and family history of hypocalcemia. Further steps include:
Physical exam for neuromuscular symptoms, including Chvostek’s sign (facial twitching in response to stimulation) and Trousseau’s sign (muscle spasms in the hand and forearm)
Blood tests for total serum calcium, ionized calcium (calcium that is flowing freely in your blood), magnesium, phosphorus, vitamin D, and parathyroid hormone
Urine test for excessive excretion of calcium and to check kidney function
Your doctor may also test your heart for rhythm abnormalities, check your eyes for cataracts, image your kidneys to look for calcium deposits, and perform a bone density scan. He or she may also perform additional blood tests to rule out other causes of hypocalcemia.
Making the diagnosis
If tests show that you have low ionized calcium (calcium that is flowing freely in your blood), inappropriately low PTH, and high phosphorus, this could indicate that hypoparathyroidism is the cause of your hypocalcemia.
How is hypoparathyroidism monitored?
Your doctor will want to keep an eye on your condition by monitoring certain tests periodically, especially:
- Blood tests for calcium, phosphate, magnesium, and kidney function
- 24-hour urine collection for calcium levels and to check kidney function
Your doctor may choose to do these tests more often if they feel it is needed to monitor your condition. Your doctor may also choose to do additional regular tests, such as taking images of your kidneys or brain to look for calcium deposits, examining your eyes for cataracts, and following your bone density.
What are my doctor’s goals for me?
Your doctor will work with you to help you achieve the following goals:
- Prevent symptoms of low blood calcium
- Keep your blood calcium level slightly below normal or in the low normal range
- Keep your blood calcium and blood phosphate in balance
- Avoid excessive calcium in your urine
- Avoid excessive calcium in your blood
- Avoid calcium being deposited in your kidneys and other soft tissues
Can hypoparathyroidism be treated?
Treatments to help manage hypoparathyroidism are available. Speak to your doctor to learn more.
Is there support for people with hypoparathyroidism?
Offers information about clinical trials and organizes events that support patients and families affected by hypoparathyroidism.
Provides online resources and organizes conferences to educate and support those touched by hypoparathyroidism.
Works to improve the quality of life of thyroid cancer patients through education and research.
Provides free support services, educational events, and thyroid cancer research grants.
Shire provides funding to the above organizations in support of efforts that include, but are not limited to: research, education, meetings/events, and patient support.
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