What is hyperparathyroidism?

Hyperparathyroidism is a condition in which one or more of the parathyroid glands become overactive and secrete too much parathyroid hormone (PTH). This causes the levels of calcium in the blood to rise, a condition known as hypercalcemia.

What are the parathyroid glands?

Throid Anatomy

The parathyroid glands secrete PTH to help control the levels of calcium and phosphorous in the body. There are usually four parathyroid glands, located on the outside borders of the thyroid gland in the front of the neck.

How does hyperparathyroidism occur?

There are 2 types of hyperparathyroidism, primary and secondary:

  • In primary hyperparathyroidism, the parathyroid glands spontaneously produce an excessive amount of PTH, which causes the level of calcium in the blood to rise.
  • In secondary hyperparathyroidism, the overactivity of the parathyroid glands occurs in a condition such as kidney failure where calcium levels tend to be low, and the parathyroid overactivity is an attempt on the body's part to keep the calcium levels normal.

The cause of primary hyperparathyroidism is not fully understood. In most cases, a benign (noncancerous) growth called an adenoma forms on a single parathyroid gland and causes it to become overactive. Another cause is a condition called hyperplasia, in which 2 or more of the parathyroid glands become enlarged.

Approximately 100,000 people develop hyperparathyroidism in the United States every year. Older women who are postmenopausal are at the highest risk for the disease.

What are the symptoms of hyperparathyroidism?

In many instances, a person who has hyperparathyroidism doesn't have any symptoms. A person who has mild hyperparathyroidism may have some of the following symptoms:

  • Joint pain
  • Muscle weakness
  • Fatigue
  • Depression
  • Trouble concentrating
  • Loss of appetite

More severe cases of hyperparathyroidism may produce these symptoms:

  • Nausea and vomiting
  • Confusion
  • Increased thirst and need to urinate

Other problems associated with a severe case of hyperparathyroidism include:

  • Reduced kidney function, which affects the kidney's ability to filter blood
  • Kidney stones
  • Thinning bones (osteoporosis)

High blood pressure occurs more commonly in people with hyperparathyroidism and may need to be treated whether or not specific treatment is recommended for the hyperparathyroidism.

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