Hypercalcemia and Parathyroid Disorders
The parathyroid glands are pea-shaped glands, four in number, present on the thyroid gland in the neck. The parathyroid glands secrete the parathyroid hormone that regulates the calcium level in the body. Hyperparathyroidism is a condition characterized by excessive secretion of parathyroid hormone (PTH), into the bloodstream. Over secretion of the parathyroid hormone results in increased levels of calcium in the bloodstream, also known as hypercalcemia. Primary hyperparathyroidism is the most common cause of hypercalcemia.
Hypercalcemia can be classified into primary or parathyroid mediated and secondary or non-parathyroid mediated hypercalcemia. The primary cause of hypercalcemia is hyperparathyroidism or excess secretion of the parathyroid due to enlargement of one or more of the parathyroid glands or over activity of the parathyroid gland. The causes of non-parathyroid hypercalcemia include presence of malignancy, other endocrinal disorders such as adrenal disorder or hyperthyroidism, any inherited condition that affects the calcium metabolism, kidney failure, certain diseases such as tuberculosis, lung infection or sarcoidosis, certain drugs and intake of high calcium and vitamin D dietary supplements. Other causes of hypercalcemia include prolonged immobilization and dehydration.
In cases of mild hypercalcemia the patient may not experience any signs or symptoms or experience only a few symptoms. In severe cases, patient may develop certain symptoms such as nausea, vomiting, loss of appetite, excessive thirst, polyuria or frequent urination, constipation, abdominal pain, muscle weakness, pain in the joint and muscles and fatigue.
Diagnosis of hypercalcemia is based on blood tests for serum calcium, PTH, vitamin D levels, and elevated blood levels of parathyroid hormone as well as tests for urine calcium. In the cases of non-parathyroid mediated hypercalcemia other tests such as chest X-ray, mammogram, CT or MRI scan may be used to diagnosis underlying cause.
The treatment of hyperparathyroidism depends upon the severity and the underlying cause of hyperparathyroidism. The common treatment options for the management of hyperparathyroidism include:
- Regular exercise
- Estrogen therapy, for postmenopausal women
- Medication such as bisphosphonates and calcitonin to reduce calcium levels in the blood stream
- Avoid certain medications such as thiazide-type diuretics
- Increased intake of fluid to prevent the formation of kidney stones
In cases where conservative treatment options fail to provide any benefit, the parathyroid gland can be surgically removed to decrease the production of the parathyroid hormone. Surgery is generally recommended for patients below 50 years of age.
In severe cases of hypercalcemia, hospitalization is required to reduce serum calcium levels to protect the kidneys and bones. The treatment includes intravenous fluids, loop diuretic medications, calcitonin, glucocorticoids and hemodialysis or peritoneal dialysis.
The associated complications of hypercalcemia include osteoporosis, kidney stones or failure, neurological disorder, pancreatitis and arrhythmia or abnormal heart rhythm.
Parathyroid glands are oval, grain-of-rice shaped situated in the neck. These glands maintain the calcium and phosphorous level in the body by regulating the secretion of parathyroid hormone. The gland secrets parathyroid hormone when there is lower calcium level and that restore the balance by releasing the calcium from the bone. Any dysfunction of the gland may increase the level of parathyroid hormone and that may induce the release of calcium and may cause hypercalcaemia. Hyperparathyroidism is the chief disorder of the parathyroid gland disorder and it causes hyper production of the parathyroid hormone.
The causes of the parathyroid disorder can be divided into primary and secondary. The primary cause of the disorder is hyperparathyroidism and it is caused due to over production of the parathyroid hormone from the parathyroid glands. Any non-cancerous growth, hyperplasia or enlargement of the gland and any cancerous growth may be the reason of the hyper production of the gland. The secondary causes of the disorder may be severe calcium deficiency or severe vitamin deficiency and chronic kidney failure that may lower the calcium levels and leads the gland to overwork.
The signs and symptoms of the parathyroid disorder usually develop after the damage or dysfunction of the involved organs or tissues. The symptoms of the disorder include osteoporosis, kidney stones, fatigue, abdominal pain, frequent urination, pain in the bone and joint or frequent illness, nausea, vomiting or loss of appetite and depression or forgetfulness.
The diagnosis of the parathyroid disorder includes blood test that reveals the elevated calcium level in the blood and confirms the condition. Additional tests such as bone mineral density test to measure the quantity of the calcium and other mineral in a segment of bone, urine test to check the urinary function and the excreted calcium in the urine. Imaging test also may be used to determine any kidney stone or other abnormalities of kidney.
If surgery is required other advance imaging such as ultrasound or sestamibi scan may be used to detect the abnormality.
The treatment of the condition involves a careful monitoring of the patient to check elevation of the blood calcium level and medications for hyperparathyroidism such as hormone replacement therapy, calciminetics and bisphosphonates may be given. Surgery is the most common treatment measure for this condition and it involves the removal of the affected part of the gland.
The possible complications related to parathyroid disorder include osteoporosis, presence of kidney stone, cardiovascular diseases and neonatal hyperparathyroidism.