| Signs and symptoms |
More than half the people with hyperparathyroidism have no symptoms. In those who do, the symptoms are frequently subtle, such as a feeling of weakness or fatigue, or vague aches and pains. But more severe signs and symptoms can develop over time, including:
- Increased thirst and urination due to increased excretion of calcium in the urine (hypercalciuria)
- Kidney stones
- Heartburn from peptic ulcer disease or pancreatitis
- Nausea, vomiting or loss of appetite
- Thinning bones, leading to an increased risk of fractures
- Confusion or poor memory
- Muscle weakness or fatigue
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| Causes |
Calcium is the most abundant mineral in your body. It's essential for the development and health of your teeth and bones. Calcium also helps your blood clot, aids in the transmission of signals in nerve cells and plays a role in muscle contraction. Another mineral, phosphorus, works in conjunction with calcium in these areas.
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 as a thermostat controls a heating system to maintain a constant air temperature. Vitamin D is also 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 the right amount of 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 parathyroids produce less PTH.
But sometimes one or more parathyroid glands produce too much hormone, leading to abnormally high levels of calcium and low levels of phosphorus in your blood.
In more than 80 percent of people with the disorder, the cause is a benign growth (adenoma) on one of the parathyroid glands. In most other cases, excess hormone is produced when two or more parathyroids become enlarged — a condition known as hyperplasia.
Secondary hyperparathyroidism occurs when another medical condition, such as kidney failure, causes your parathyroid to produce too much PTH. Infants and children who have rickets — a disease caused by severe vitamin D deficiency — may also develop secondary hyperparathyroidism.
In very rare cases, hyperparathyroidism may be caused by cancer of one of the parathyroid glands.
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| Risk factors |
Twice as many women as men develop primary hyperparathyroidism, and risk increases with age. Two out of every 1,000 women age 60 and older will develop the disease.
Infants or adults with vitamin D deficiency are also at greater risk of developing secondary hyperparathyroidism. Most children and adults get sufficient amounts of vitamin D from foods such as eggs, fish, green vegetables and fortified milk products, and from exposure to sunlight, which changes a chemical in the skin into an active form of vitamin D. But several factors have caused a resurgence of vitamin D deficiency among some infants and children.
Chief among these are breast-feeding and the use of sunscreen. Although breast milk is a baby's ideal food, it doesn't contain vitamin D. If your baby is breast-fed only, talk to your pediatrician about a vitamin D supplement. In addition, children who live in northern or cloudy climates or who consistently use sunscreen may not receive enough sunlight to manufacture vitamin D in their skin.
Also at increased risk are people with familial endocrine neoplasia, type I — a rare inherited syndrome that affects the parathyroids as well as the pancreas and pituitary gland. Having familial hyperparathyroidism — hyperparathyroidism that runs in families — also puts you at risk.
| Screening and diagnosis |
You may not realize you have hyperparathyroidism because early symptoms tend to be vague or nonexistent. When symptoms do develop, they frequently resemble those of other conditions. That's why doctors rely on blood tests to diagnose hyperparathyroidism.
In fact, your doctor may be alerted to the disease when high levels of calcium show up on routine blood tests, or on tests that screen for a number of conditions, including increased levels of calcium. But because other diseases and certain medications also can increase the amount of calcium in your blood, you'll receive a diagnosis of hyperparathyroidism only if blood tests show high levels of both calcium and parathyroid hormone.
One condition unrelated to hyperparathyroidism that increases blood-calcium levels is sarcoidosis — an inflammatory condition that can affect virtually any organ in your body. In addition, breast and lung cancers may secrete a substance that increases calcium concentrations. Multiple myeloma — a type of cancer affecting certain white cells (plasma cells) — and bone metastases also cause an increase in blood calcium. That's because these cancers cause the bones to break down, releasing calcium into the bloodstream.
Medications such as thiazide diuretics used to treat high blood pressure and lithium (Eskalith, Lithobid), which treats certain mental disorders, can boost blood-calcium levels as well.
Once hyperparathyroidism is diagnosed, your doctor may recommend tests to check for complications. These may include bone density tests to assess bone loss, and a 24-hour collection of urine to provide information on your kidney function.
If your doctor suspects you have kidney stones, he or she may also suggest an abdominal X-ray or ultrasound — a diagnostic technique that combines high-frequency radio waves and computer processing to view internal organs.
Sometimes you and your doctor may choose not to treat hyperparathyroidism right away. If so, your doctor will likely want to check your calcium levels and kidney function every 6 months. He or she may also recommend an annual abdominal X-ray and a bone density test every 1 to 2 years. If the disease doesn't become worse over time, you may not need to have these tests as often.
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| Complications |
Hyperparathyroidism poses a long-term threat to your bones — the more PTH the parathyroids produce, the more calcium your bones lose. The result may be osteoporosis. This condition can make bones so brittle and weak that even small stresses such as bending over or coughing can cause a fracture.
Because your body tries to compensate for excess calcium by excreting more of the mineral in your urine, you are also at risk of kidney damage or kidney stones.
These stones can occur when calcium and other substances in your urine form crystals on the inner surfaces of your kidneys. Over time the crystals may combine to create a small, hard mass (stone). Sometimes the stone breaks off and passes into the ureter, one of the two thin tubes leading from your kidneys to your bladder.
Most smaller kidney stones pass into your bladder without causing any permanent damage. But larger stones occasionally block the ureters or the outlet from the bladder itself and may cause ongoing urinary tract infection or kidney damage.
If a stone stays inside one of your kidneys, it usually doesn't cause a problem unless it becomes so large it blocks the flow of urine. Then it can cause acute pressure and pain, and increase the risk of kidney damage, bleeding and infection.
High blood levels of calcium stimulate your stomach to produce more acid, which makes it more likely you'll develop peptic ulcers. Having hyperparathyroidism also increases your risk of pancreatitis — an inflammation of your pancreas — and high blood pressure.
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| Treatment |
In general, treatment depends on the presence of complications or symptoms and the type of hyperparathyroidism you have.
Primary hyperparathyroidism
If you don't have symptoms and your kidneys and bones are healthy, you and your doctor may choose a wait-and-see approach. Sometimes this may be all that is needed, although your kidney function, bone health and calcium levels will need to be monitored on a regular basis.
If your symptoms are moderate to severe or you have complications, your doctor will likely recommend surgery to remove one or more parathyroid glands (parathyroidectomy). In cases where the problem is an adenoma, just the one gland will be removed. If all four glands are enlarged, your surgeon will likely remove three of them and sometimes part of the fourth.
Traditionally, this surgery has involved a long incision, exploration on both sides of the neck and general anesthesia. But a newer technique, known as minimally invasive radioguided parathyroidectomy (MIRP), may offer a safer and less invasive approach for some people. In this procedure, doctors use a radioisotope scan (sestamibi scan) to help locate a tumor or abnormal parathyroid gland prior to surgery.
For the scan, you're given a very small dose of a radioactive material that's absorbed only by the overactive parathyroid gland — not healthy ones. During the operation, the surgeon uses the sestamibi scan results as a map to locate the abnormal gland. In some cases, a probe that detects radioactivity, much as a Geiger counter does, is used to confirm the location.
The entire operation can usually be performed through a 1-inch incision in you neck. It takes less than an hour and generally requires local rather than general anesthesia. If local anesthesia is used, you likely can go home a few hours after surgery.
Still, all surgery poses some risks. About 1 percent of people undergoing parathyroid surgery experience damage to the nerves controlling their vocal cords, and between 1 percent and 5 percent develop chronically low calcium levels, requiring treatment with calcium and vitamin D. In addition, although parathyroid surgery is usually very effective, it won't cure the problem in every case.
For women who have gone through menopause and have signs of osteoporosis but no other symptoms, hormone replacement therapy (HRT) may be an alternative to surgery. That's because HRT is currently the best way to prevent osteoporosis.
But not all effects of HRT are positive. HRT increases your risk of blood clots and gallbladder and heart diseases. And taking HRT as a combination therapy — estrogen with medroxyprogesterone acetate (such as Prempro) — for several years or more may increase your risk of breast cancer. All combination HRT regimens can cause irregular vaginal bleeding, particularly during the first year of use. Further study is needed to determine to what extent estrogen-only therapy increases your risk of breast cancer. The long-term benefits of HRT are therefore under intense scrutiny.
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Secondary hyperparathyroidism
In cases of secondary hyperparathyroidism, the first goal is to treat the underlying problem. For many adults, that problem is chronic kidney failure. Because treatments used to manage kidney failure won't cure hyperparathyroidism, vitamin D hormone replacement therapies will likely be used to reduce the production of PTH.
For infants or children who have rickets, vitamin D supplements will also successfully treat hyperparathyroidism.
| Self-care |
If you're monitoring your hyperparathyroidism, your efforts can play a role in preventing complications. Here are some suggestions for staying as healthy as possible:
- Drink plenty of fluids, especially water. Drinking lots of fluids can help prevent kidney
stones from forming.
- Exercise. This is one of the best ways to build strong bones and slow bone loss. Try to
combine strength training with weight-bearing exercises. Strength training builds muscles and bones in
your arms and upper spine, while weight-bearing exercises — such as walking, jogging, running, stair
climbing, skipping rope, skiing and impact-producing sports — mainly affect the bones in your legs,
hips and lower spine. If you're new to exercise, start out slowly and build up gradually. Aim for at
least 30 minutes of exercise on most days.
- Consider hormone replacement therapy. Hormone replacement therapy (HRT) is the single most
important way to reduce a woman's risk of osteoporosis during and after menopause.
- Get adequate amounts of vitamin D. Premenopausal women and postmenopausal women who use HRT
should consume at least 400 international units of vitamin D every day. Postmenopausal women not using
HRT should get 800 international units of vitamin D daily.
- Don't smoke. Smoking has been shown to increase bone loss.
- Be alert for conditions that may increase your calcium levels. Certain conditions, such as gastrointestinal illnesses with vomiting and diarrhea, can cause your blood-calcium levels to rise. Call your doctor if you develop any of these symptoms.
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