Hyperparathyroidism – symptoms, diagnosis and treatment electricity generation by source by country

#

The parathyroid glands are normally located on the thyroid gland in the neck. Occasionally, a person is born with one or more of the parathyroid glands embedded in the thyroid, the thymus, or somewhere in the chest. In most such cases, however, the glands function normally.

Although their names are similar, the thyroid and parathyroid glands are entirely separate glands, each producing distinct hormones with specific functions. The parathyroid glands secrete parathyroid hormone (PTH), a substance that helps maintain the correct balance of calcium and phosphorous in the body. PTH regulates release of the calcium from bone, absorption of calcium in the intestine, and excretion of calcium in the urine. When the amount of calcium in the blood falls too low, the parathyroid glands secrete just enough PTH to restore the balance.

If the glands secrete too much hormone, as in hyperparathyroidism, the balance is disrupted: blood calcium rises. This condition, called hypercalcemia, is what usually signals the doctor that something may be wrong with the parathyroid glands. In 85% of people with this disorder, a benign tumor ( adenoma) has formed on one of the parathyroid glands, causing it to become overactive. In most other cases, the excess hormone comes from two or more enlarged parathyroid glands, a condition called hyperplasia. Very rarely, hyperparathyroidism is caused by cancer of a parathyroid gland.

Excess PTH triggers the release of too much calcium into the bloodstream. The bones may lose calcium, and too much calcium may be absorbed from food. The levels of calcium may increase in the urine, causing kidney stones. PTH also acts to lower blood phosphorous levels by increasing excretion of phosphorus in the urine. Causes and Development

In most cases the cause is unknown, occurring in people with no family history of the disorder. Only about 3-5% of cases can be linked to an inherited problem. Familial endocrine neoplasia type I is one rare inherited syndrome that affects the parathyroids as well as the pancreas and the pituitary gland. Another rare genetic disorder, familial hypocalciuric hypercalcemia, is sometimes confused with typical hyperparathyroidism. Diagnosis and Tests

A person with hyperparathyroidism may have severe symptoms, subtle ones, or none at all. Increasingly, routine blood tests that screen for a wide range of conditions including high calcium levels are alerting doctors to people who, though symptom-free, have mild forms of the disorder.

Hyperparathyroidism is diagnosed when tests show that blood levels of calcium as well as parathyroid hormone are too high. Other diseases can cause high blood calcium levels, but only in hyperparathyroidism is the elevated calcium the result of too much parathyroid hormone. A blood test that accurately measures the amount of parathyroid hormone has simplified the diagnosis of hyperparathyroidism.

Once the diagnosis is established, other tests may be done to assess complications. Because high PTH levels can cause bones to weaken from calcium loss, a measurement of bone density may be done to assess bone loss and the risk of fractures. Abdominal radiographs may reveal the presence of kidney stones and a 24-hour urine collection may provide information on kidney damage and the risk of stone formation. Treatment and Prevention

Some patients who have mild disease may not need immediate treatment, according to a panel of experts convened by the National Institutes of Health in 1990. Patients who are symptom-free, whose blood calcium is only slightly elevated, and whose kidneys and bones are normal, may wish to discuss long-term monitoring. In the panel’s recommendation, monitoring would consist of clinical evaluation and measurement of calcium levels and kidney function every 6 months, annual abdominal X-ray, and bone mass measurement after 1 to 2 years. If the disease shows no signs of worsening after 1 to 3 years, the interval between exams may be lengthened. Immobilization and gastrointestinal illness with vomiting or diarrhea can cause calcium levels to rise, and if these conditions develop, patients with hyperparathyroidism should seek medical attention. Prognosis; Complications