The cause of secondary hyperparathyroidism is not actually a problem in the parathyroid glands. Rather, it results when diseases afflict other parts of the body and cause the parathyroids to secrete excessive levels of parathyroid hormone, leading to high levels of calcium in the bloodstream. Examples of these diseases include rickets, vitamin D deficiency, and chronic renal failure.
Excessive secretion of parathyroid hormone promotes reabsorption of calcium from the bloodstream by causing the body’s bone to degrade. This leads to a condition with brittle bones called osteitis fibrosa and causes bone pain, bone deformities, and pathological fractures. In addition, excessive secretion of parathyroid hormone causes calcium deposition at various sites (ectopic calcification), leading to diseases such as arteriosclerosis, valvular heart disease, and arthritis.
Regular blood tests are used to show levels of calcium, phosphorus, and parathyroid hormone. It is important to prevent the development of renal hyperparathyroidism. Common measures include following a medically designed diet, oral or intravenous administration of active vitamin D3, and medications such as phosphate binders. However, if the disease progresses, enlarged parathyroid glands will need to be examined using a variety of techniques, including ultrasonography (echography), computed tomography (CT scan), magnetic resonance imaging (MRI), and isotope examination (methoxy-isobutyl-isonitrile [MIBI] scintigraphy). Treatment methods include percutaneous ethanol injection therapy (PEIT), vitamin D3 injection therapy, and surgery.
If surgery is pursued, the standard practice is to remove all parathyroid glands from the neck area and then transplant a portion of the glands into the forearm.