What To Think About

• Because PTH can raise calcium levels and lower phosphorus levels, blood tests for calcium and phosphorus are often done at the same time as a test for PTH. For more information, see the medical tests Calcium (Ca) in Blood, Phosphate in Blood, and Total Serum Protein.
• How well your kidneys work can affect how much PTH you have in your blood. For this reason, tests to measure the amount of creatinine in the blood may be done at the same time as a PTH test. For more information, see the medical test Creatinine and Creatinine Clearance.
• A high PTH level along with a high calcium level can cause problems such as osteoporosis, kidney stones, hypertension, kidney failure, peptic ulcer disease, cognitive changes, and problems with the balance of water in the body. About half of all people who have high levels of PTH and calcium in the blood need treatment to correct the abnormal levels. Further testing, such as bone mineral density testing or 24-hour urine calcium testing, may be needed to help make decisions about treatment. For more information, see the medical tests Bone Mineral Density or Calcium (Ca) in Urine.
• An overactive parathyroid gland is often caused by a noncancerous (benign) tumor of the parathyroid gland. Parathyroid tumors tend to grow slowly and may not cause any symptoms for many years. Parathyroid tumors are more common after age 50 and are often found with routine blood tests that are done for other reasons. Treatment includes close observation, medicines, or surgery to remove the tumor.

Other Works Consulted

• Pagana KD, Pagana TJ (2006). Mosby’s Manual of Diagnostic and Laboratory Tests, 3rd ed. St. Louis: Mosby.