Hyperparathyroidism is when your parathyroid glands create too much parathyroid hormone in the bloodstream. These glands, located behind the thyroid at the bottom of your neck, are about the size of a grain of rice.
The parathyroid glands produce parathyroid hormone. This hormone helps maintain an appropriate balance of calcium in the bloodstream and in tissues that depend on calcium for proper functioning.
Two types of hyperparathyroidism exist. In primary hyperparathyroidism, an enlargement of one or more of the parathyroid glands causes overproduction of the hormone. This causes high calcium levels in the blood, which can cause a variety of health problems. Surgery is the most common treatment for primary hyperparathyroidism.
Secondary hyperparathyroidism occurs due to another disease that first causes low calcium levels in the body. Over time, increased parathyroid hormone levels occur.
Hyperparathyroidism is often diagnosed before signs or symptoms of the disorder are apparent. When symptoms do occur, they're the result of damage or dysfunction in other organs or tissues due to high calcium levels in the blood and urine or too little calcium in bones.
Symptoms may be so mild and nonspecific that they don't seem related to parathyroid function, or they may be severe. The range of signs and symptoms include:
See your doctor if you have any signs or symptoms of hyperparathyroidism. These symptoms could be caused by any number of disorders, including some with serious complications. It's important to get a prompt, accurate diagnosis and appropriate treatment.
Hyperparathyroidism is caused by factors that increase the production of parathyroid hormone.
The parathyroid glands maintain proper levels of both calcium and phosphorus in your body by turning the secretion of parathyroid hormone (PTH) off or on, much like a thermostat controls a heating system to maintain a constant air temperature. Vitamin D also is involved in regulating the amount of calcium in your blood.
Normally, this balancing act works well. When calcium levels in your blood fall too low, your parathyroid glands secrete enough PTH to restore the balance. PTH raises calcium levels by releasing calcium from your bones and increasing the amount of calcium absorbed from your small intestine.
When blood-calcium levels are too high, the parathyroid glands produce less PTH. But sometimes one or more of these glands produce too much hormone. This leads to abnormally high calcium levels and low phosphorus levels in your blood.
Calcium is best known for its role in keeping your teeth and bones healthy. But calcium also aids in the transmission of signals in nerve cells, and it's involved in muscle contraction. Phosphorus, another mineral, works along with calcium in these areas.
Hyperparathyroidism may occur because of a problem with the parathyroid glands (primary hyperparathyroidism) or because of another disease that affects the glands' function (secondary hyperparathyroidism).
Primary hyperparathyroidism occurs because of some problem with one or more of the four parathyroid glands:
Primary hyperparathyroidism usually occurs randomly, but some people inherit a gene that causes the disorder.
Secondary hyperparathyroidism is the result of another condition that lowers calcium levels. This causes your parathyroid glands to overwork to compensate for the calcium loss. Factors that may contribute to secondary hyperparathyroidism include:
Severe vitamin D deficiency. Vitamin D helps maintain appropriate calcium levels in the blood. It also helps your digestive system absorb calcium from your food.
Your body produces vitamin D when your skin is exposed to sunlight. You also consume some vitamin D in food. If you don't get enough vitamin D, then calcium levels may drop.
Chronic kidney failure. Your kidneys convert vitamin D into a form that your body can use. If your kidneys work poorly, usable vitamin D may decline and calcium levels drop, causing parathyroid hormone levels to go up. Chronic kidney failure is the most common cause of secondary hyperparathyroidism. Some medical treatments, such as vitamin D, bisphosphonates and cinacalcet, will lower PTH levels.
In some people with long-term end-stage kidney disease, the parathyroid glands enlarge and begin to release PTH on their own, and PTH doesn't go down with medical treatment. This is called tertiary hyperparathyroidism, and people with this condition may require surgery to remove parathyroid tissue.
You may be at an increased risk of primary hyperparathyroidism if you:
Complications of hyperparathyroidism are mainly related to the long-term effect of too little calcium in your bones and too much calcium in your bloodstream. Common complications include:
If blood test results show you have high calcium levels in your blood, your doctor will likely repeat the test to confirm the results after you haven't eaten for a period of time.
Many conditions can raise calcium levels. But your doctor can diagnose hyperparathyroidism if blood tests show you also have high levels of parathyroid hormone.
After diagnosing hyperparathyroidism, your doctor will likely order more tests to rule out possible secondary causes, to identify possible complications and to judge the severity of the condition. These tests include:
Bone mineral density test. This test is done to see if you have developed osteoporosis. The most common test to measure bone mineral density is dual energy X-ray absorptiometry (DEXA).
This test uses special X-ray devices to measure how many grams of calcium and other bone minerals are packed into a bone segment.
Urine test. A 24-hour collection of urine can provide information on how well your kidneys work and how much calcium is excreted in your urine.
This test may help in judging the severity of hyperparathyroidism or diagnosing a kidney disorder causing hyperparathyroidism. If a very low calcium level is found in the urine, this may mean it's a condition that doesn't need treatment.
If your doctor recommends surgery, he or she will likely use one of these imaging tests to locate the parathyroid gland or glands that are causing problems:
Sestamibi parathyroid scan. Sestamibi is a radioactive compound that is absorbed by overactive parathyroid glands and can be detected by a scanner that detects radioactivity.
The normal thyroid gland also absorbs sestamibi. To eliminate uptake in the thyroid obscuring the uptake in a parathyroid adenoma, radioactive iodine, which is only taken up by the thyroid, also is given and the thyroid image is digitally subtracted.
Computerized tomography (CT) scanning may be combined with the sestamibi scan to improve detection of an abnormality.
Ultrasound. Ultrasound uses sound waves to create images of your parathyroid glands and surrounding tissue.
A small device held against your skin (transducer) emits high-pitched sound waves and records the sound wave echoes as they reflect off internal structures. A computer converts the echoes into images on a monitor.
Your doctor may recommend no treatment and regular monitoring if:
If you choose this watch-and-wait approach, you'll likely need periodically scheduled tests to monitor your blood-calcium levels and bone density.
Surgery is the most common treatment for primary hyperparathyroidism and provides a cure in most cases. A surgeon will remove only those glands that are enlarged or have a tumor.
If all four glands are affected, a surgeon will likely remove only three glands and perhaps a portion of the fourth — leaving some functioning parathyroid tissue.
Surgery may be done as an outpatient procedure, allowing you to go home the same day. In such cases, the surgery can be done through very small cuts (incisions) in the neck, and you receive only local anesthetics.
Complications from surgery aren't common. Risks include:
Medications to treat hyperparathyroidism include the following:
Calcimimetics. A calcimimetic is a drug that mimics calcium circulating in the blood. The drug may trick the parathyroid glands into releasing less parathyroid hormone. This drug is sold as cinacalcet (Sensipar).
Some doctors may prescribe cinacalcet to treat primary hyperparathyroidism, particularly if surgery hasn't successfully cured the disorder or a person isn't a good surgery candidate.
The most commonly reported side effects of cinacalcet are joint and muscle pain, diarrhea, nausea, and respiratory infection.
Hormone replacement therapy. For women who have gone through menopause and have signs of osteoporosis, hormone replacement therapy may help bones retain calcium. This treatment doesn't address the underlying problems with the parathyroid glands.
Prolonged use of hormone replacement therapy can increase the risk of blood clots and breast cancer. Work with your doctor to evaluate the risks and benefits to help you decide what's best for you.
Some common side effects of hormone replacement therapy include breast pain and tenderness, dizziness, and headaches.
If you and your doctor have chosen to monitor, rather than treat, your hyperparathyroidism, the following suggestions can help prevent complications:
Monitor how much calcium and vitamin D you get in your diet. Restricting dietary calcium intake isn't advised for people with hyperparathyroidism.
The daily recommended amount of calcium for adults ages 19 to 50 and men ages 51 to 70 is 1,000 milligrams (mg) of calcium a day. That calcium recommendation increases to 1,200 mg a day for women age 51 and older and men age 71 and older.
The daily recommended amount of vitamin D is 600 international units (IUs) of vitamin D a day for people ages 1 to 70 and 800 IUs a day for adults age 71 and older. Talk to your doctor about dietary guidelines that are appropriate for you.
In most cases, elevated calcium is detected by blood tests your doctor has ordered as part of a routine screening, a diagnostic work-up for an unrelated condition or a diagnostic work-up to identify the cause of very general symptoms.
Talk to your doctor about test results if they show you have high levels of calcium. Questions you might ask your doctor include:
To understand the effect of hyperparathyroidism on your overall health, your doctor may ask you questions about possible mild signs or symptoms, including:
Your doctor may ask you additional questions about what medications you're taking and what your diet is like to help determine if you get adequate amounts of calcium and vitamin D.
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