Parathyroid-related hypercalcemia

Definition

Primary hyperparathyroidism is an endocrine disorder in which the body has too much parathyroid hormone (PTH).

Alternative Names

Causes

The parathyroid glands are located at the front and base of the neck at the four corners of the thyroid gland. The glands produce parathyroid hormone, which controls the amount of calcium and phosphorus in the body.

In primary hyperparathyroidism, enlargement of one or more of the parathyroid glands causes extra parathyroid hormone to be released. This increases calcium levels. The effects of increased calcium are seen in several body systems including the skeletal, gastrointestinal, renal (kidney), muscular, and central nervous system.

The disease is most common in people over 60, but can also be seen in younger adults. Women are more likely to be affected than men. Radiation to the head and neck increases risk. Hyperparathyroidism in childhood is very unusual.

Rarely, the disease is caused by parathyroid cancer.

Symptoms

• Fatigue
• Fractures
• Decreased height
• Upper abdominal pain
• Loss of appetite
• Nausea
• Muscular weakness
• Muscle pain
• Depression
• Personality changes
• Stupor and possibly coma
• Kidney stones
• Increased urination

Exams and Tests

• A test called radioimmunoassay shows an increased level of PTH.
• Serum calcium is increased.
• Serum phosphorus may be decreased.
• Serum alkaline phosphatase may be increased.
• Bone x-ray may show bone reabsorption (the body breaks down the bone), or fractures.
• Imaging of the kidneys or ureters may show calcification or blockage.
• ECG may show abnormalities.

This disease may cause changes in the results of the following tests:

• Calcium - urine
• Calcium (ionized)
• Bone density
• Markers of bone resorption (N-telopeptide, pyridinoline, and deoxypyridinoline)

Treatment

Treatment depends upon the severity and cause of the condition. If calcium levels are mildly high, they may simply be monitored, but not treated, unless the kidneys do not work correctly, kidney stones develop, or there is a loss of calcium from bones, which makes them weaker.

Treatment may include:

• Drinking more fluids to prevent the formation of kidney stones
• Movement and exercise
• Avoiding immobilization
• Avoiding thiazide-type diuretics ("water pills")
• Using estrogen therapy (for postmenopausal women)
• Treating with a calcium-receptor sensitizer (cinacalcet) to decrease levels of PTH

For severe cases that cause problems, hospitalization may be required. An IV may be used to replace fluids (rehydrate the body). Medications to bring down calcium levels quickly may be given. They include bisphosphonates and calcitonin

Surgery to remove the tumor or removal of excess parathyroid tissue resulting from hyperplasia is necessary for severely high calcium levels or one or more of the following complications are present: kidney stones, pancreatitis

Surgery is also recommended for patients less than 50 years of age.

Outlook (Prognosis)

The prognosis is good for mild cases. Most cases of primary hyperparathyroidism are mild.

Possible Complications

Complications that result from excess calcium deposits within the body:

• Skeletal damage
• Urinary tract infection due to kidney stones and obstruction
• Pancreatitis
• Pseudogout

When to Contact a Medical Professional

Call for an appointment with your health care provider if symptoms indicate that primary hyperparathyroidism may be present.

Call your health care provider if signs of complications develop.