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Definition

The parathyroid glands are four small glands in the neck. They secrete parathyroid hormone (PTH). PTH controls the level of calcium in the blood.

In hyperparathyroidism too much PTH is secreted. This causes high levels of calcium in the blood. High calcium is known as hypercalcemia. The condition is classified as being:

  • Primary hyperparathyroidism—most common form
  • Secondary hyperparathyroidism—occurs in patients with kidney failure]]> or a severe ]]>vitamin D]]> deficient state
  • Tertiary hyperparathyroidism—also occurs in patients with kidney failure or a severe vitamin D deficient state

Thyroid and Parathyroid Glands: Posterior (Back) View

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© 2008 Nucleus Medical Art, Inc.

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Causes

In most cases, the exact cause is not known. Factors that may contribute to hyperparathyroidism include:

  • Adenoma (benign tumor) in the parathyroid gland (accounting for 85% of primary hyperparathyroidism)
  • Hyperplasia (enlargement) of the parathyroid glands (accounting for over 80% of secondary or tertiary hyperparathyroidism)
  • Parathyroid cancer
  • Familial hyperparathyroidism
  • Vitamin D deficiency (due to malabsorption, lack of sunlight exposure, inadequate dietary intake)
  • Radiation therapy]]> to head or neck during childhood
  • Multiple endocrine neoplasia (MEN)
  • Kidney failure or other medical problems that make the body resistant to the action of the parathyroid hormone (called secondary hyperparathyroidism)

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Risk Factors

The following factors increase your chance of developing hyperparathyroidism:

  • Sex: female (hyperparathyroidism is three times more common in women, especially after menopause]]> )
  • Age: older than 60 years
  • Multiple endocrine neoplasia (an inherited disorder that affects the endocrine glands)
  • Genetics that make you more likely to have hyperparathyroidism

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Symptoms

If you experience any of these, do not assume it is due to this condition. The symptoms may be caused by other health conditions. If you have any one of them, see your doctor.

The degree of hypercalcemia, as well as the disease progress, will determine the symptoms. Symptoms commonly seen with primary hyperparathyroidism include the following:

  • Loss of appetite
  • Thirst
  • Frequent and sometimes painful urination
  • Lethargy
  • Fatigue
  • Muscle weakness
  • Joint pain
  • Constipation]]>
  • Nausea
  • Vomiting
  • Abdominal pain
  • Memory loss
  • ]]>Depression]]>
  • ]]>Heartburn]]>
  • Back pain

Symptoms and clinical signs common to those patients with secondary or tertiary hyperparathyroidism include the following:

  • Bone pain
  • Fracture
  • Muscle weakness
  • Symptoms related to kidney failure or intestinal diseases such as malabsorption
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Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to a specialist. An endocrinologist focuses on hormones.

Tests may include the following:

  • Blood tests—to measure calcium, phosphorus, alkaline phosphatase, vitamin D, and/or PTH
  • Urine test—a 24-hour urine collection to measure calcium excretion and kidney function
  • Abdominal x-ray]]> —a test that uses radiation to take a picture of the structures inside the body; can show ]]>kidney stones]]> caused by high calcium levels
  • ]]>Bone density test]]> —a test to measure bone loss and risk of fractures
  • Neck ]]>ultrasound]]> —a test that uses sound waves to detect a large parathyroid tumor (adenoma)
  • ]]>Magnetic resonance imaging (MRI)]]> or technetium 99m sestamibi scan—a test that uses magnetic waves to make pictures of structures inside the body; to locate a single parathyroid adenoma

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Treatment

Talk with your doctor about the best plan for you. Treatment options include the following:

Medications

  • Calcitriol]]> (the most active vitamin D metabolite)—helps to reduce PTH production in secondary hyperparathyroidism in chronic kidney failure
  • ]]>Cinacalcet]]> —helps to lower PTH blood levels for secondary and tertiary hyperparathyroidism in chronic kidney disease
  • ]]>Paricalcitol]]> (a vitamin D analog)—for the prevention and treatment of secondary hyperparathyroidism associated with chronic kidney failure
  • ]]>Ergocalciferol]]> (a vitamin D analog)—for treating secondary hyperparathyroidism due to deficiency of vitamin D
  • Estrogen (hormone replacement therapy) for postmenopausal women

Surgery

A partial or complete parathyroidectomy may be done. This is the partial or total removal of the parathyroid. It may be used:

  • To remove a tumor—common in primary hyperparathyroidism and results in a 95% cure rate (calcium levels return to normal and decrease risk of bone and kidney problems)
  • To remove parathyroid tissue—common for tertiary or secondary hyperparathyroidism due to chronic renal failure; done when medical treatment has failed

Monitoring of Blood Calcium Levels

Your doctor may simply choose to regularly check your blood calcium levels. The doctor will also monitor you for possible complications. This may include regular bone density tests.

Prevention

There are no guidelines for preventing this condition.