1. Can I have an abnormal PTH level without having symptoms?
Yes, if your calcium level changes slowly, you may not have any noticeable symptoms. In this case, the imbalance will most likely be detected by finding an abnormal calcium level during a regular health check, then checking your PTH level.
If you do not have enough vitamin D, your body will not be able to absorb calcium properly. Vitamin D regulates the intestinal absorption of calcium, while PTH regulates the activation of vitamin D. Too much or too little vitamin D can cause an imbalance in calcium metabolism. During winter months with less sun exposure, especially further from the equator, vitamin D levels are typically lower and PTH levels may therefore be higher. Diet and illness may affect the magnitude of these changes.
An "intraoperative PTH" is a PTH test done on a person while that person is undergoing parathyroid gland surgery. When someone has hyperparathyroidism, the usual treatment is surgery to remove an enlarged parathyroid gland or glands. About 85-90% of the time in primary hyperparathyroidism, only one abnormal parathyroid gland is present, but in the remaining cases (and in secondary and tertiary hyperparathyroidism), two or more of the glands are abnormal.
During surgery, it is important for the surgeon to make sure that all of the abnormal glands have been removed. If all are abnormal, typically three glands are completely removed along with part of the fourth, leaving behind just enough parathyroid tissue to prevent hypoparathyroidism.
One way to be sure that all of the abnormal tissue has been removed is to measure PTH before and after a suspected abnormal gland has been removed. If all of the abnormal tissue is gone, PTH levels will fall by over 50% within 10 minutes. To be useful, this requires that the laboratory be able to provide the test results quickly. This is often called rapid or intraoperative PTH measurement.
This article was last reviewed on March 6, 2014. | This article was last modified on February 24, 2015.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
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