Hypoparathyroidism Health Dictionary

A SERUM concentration of calcium below the normal range (between 2.33 and 3.05 mmol of calcium per 100 ml of serum). This may cause TETANY, acutely; chronically it may give rise to RICKETS, OSTEOMALACIA or osteoporosis (see BONE, DISORDERS OF). It may be caused by hypoparathyroidism (see THYROID GLAND, DISEASES OF), vitamin D de?ciency (see APPENDIX 5: VITAMINS), malabsorption, renal failure or acute pancreatitis (see PANCREAS, DISORDERS OF).... hypocalcaemia

Glands that control the level of calcium in the blood. The four glands appear, two on each side, implanted in the thyroid gland in the front of the neck.

Disorders are (1) hypoparathyroidism and (2) hyperparathyroidism. See entries. ... parathyroid glands

The grouping of four small glands, about 5 mm in diameter, which lie to the side of and behind the THYROID GLAND. These glands regulate the metabolism of calcium and of phosphorus. If for any reason there is a de?ciency of the secretion of the parathyroid glands, the amount of calcium in the blood falls too low and the amount of phosphorus increases. The result is the condition known as TETANY characterised by restlessness and muscle spasms – sometimes severe. The condition is checked by the injection of calcium gluconate, which causes an increase in the amount of calcium in the blood.

The most common cause of this condition (hypoparathyroidism) is accidental injury to or removal of the glands during the operation of thyroidectomy for the treatment of Graves’ disease (see THYROID GLAND, DISEASES OF – Thyrotoxicosis). If there is over-production of the parathyroids, there will be an increase of calcium in the blood: this extra calcium is drawn from the bones, causing cysts to form with resulting bone fragility. This cystic disease of bone is known as OSTEITIS FIBROSA CYSTICA. Tumours of the parathyroid glands result in this overactivity of the parathyroid hormone, and the resulting increase in the amount of calcium in the blood leads to the formation of stones in the kidneys. The only available treatment is surgical removal of the tumour. Increased activity of the parathyroid glands, or hyperparathyroidism, may cause stones in the kidneys. (See KIDNEYS, DISEASES OF.)... parathyroid

Overproduction of parathyroid hormone by the parathyroid glands that raises the calcium level in the blood (hypercalcaemia) by removing calcium from bones. This may lead to bone disorders, such as osteoporosis. To try to normalize the high calcium level, the kidneys excrete large amounts of calcium in the urine, which can lead to the formation of kidney stones (see calculus, urinary tract).

Hyperparathyroidism is most often caused by a small noncancerous tumour of 1 or more of the parathyroid glands. It may also occur when the glands become enlarged for no known reason. It usually develops after age 40 and is twice as common in women as in men.

Hyperparathyroidism may cause depression and abdominal pain. However, often the only symptoms are those caused by kidney stones. If hypercalcaemia is severe, there may be nausea, tiredness, excessive urination, confusion, and muscle weakness.

The condition is diagnosed by X-rays of the hands and skull and by blood tests.

Surgical removal of abnormal parathyroid tissue usually cures the condition.

If the remaining tissue is unable to produce enough parathyroid hormone, treatment for hypoparathyroidism is required.... hyperparathyroidism

Spasms and twitching of the muscles, most commonly in the hands and feet, although the muscles of the face, larynx, or spine may also be affected. The spasms are caused by a biochemical disturbance and are painless at first; if the condition persists, the spasms tend to become increasingly painful. Muscle damage may result if the underlying cause is not treated. The most common underlying cause is hypocalcaemia. Other causes include hypokalaemia, hyperventilation during a panic attack, or, more rarely, hypoparathyroidism.... tetany