An Overview of Hyperparathyroidism

Hyperparathyroidism is a condition in which the parathyroid glands secrete too much parathyroid hormone, which can happen because of different medical issues. In some cases, this can cause calcium in the blood to increase to unhealthy levels, which may cause symptoms such as fatigue. Hyperparathyroidism may be a problem for roughly two or three women in 1,000, and primarily affects women over the age of 65. It is most common in post-menopausal women, but it can occur in males and females of any age.

Symptoms

Most people don’t experience any direct symptoms from their hyperparathyroidism. However, sometimes it may cause symptoms like the following:

• Fatigue
• Weakness
• Anxiety or depression
• Lack of appetite
• Abdominal pain
• Nausea and vomiting
• Constipation
• Excessive thirst
• Bone pain
• Heart rhythm problems (rarely)

Symptoms are more likely if your hyperparathyroidism is causing particularly high levels of calcium in the blood (hypercalcemia).

However, most people learn that they have hyperparathyroidism before noticing any symptoms at all. That’s because it is easily picked up on a commonly performed blood test.

Symptoms may also occur from the complications of hyperparathyroidism. For example, hyperparathyroidism puts one at an increased risk of bone breaks, due to worsened osteoporosis. It also increases the chance of having kidney stones.

Causes

To understand the potential causes of hyperparathyroidism, it is helpful to understand a little about parathyroid hormone and the parathyroid glands.

Parathyroid hormone (abbreviated PTH) is a signaling molecule, a hormone, secreted from the parathyroid glands. These four small glands are located inside the neck, near the thyroid gland.

Those medical conditions are not related to hyperparathyroidism. They just have a similar name because of their location next to the thyroid gland.

PTH plays a very important role in regulating the calcium in your body. This is critical: your heart, nervous system, and other body systems depend on having the right amount of calcium present in your blood.

If the concentration of calcium in your blood gets too low or too high, it can cause serious medical problems, such as abnormal heart rhythm.

The parathyroid glands release PTH, which sends signals to various parts of your body as it travels through the blood. These signals work to increase the amount of calcium in the blood in different ways.

For example, when they sense PTH, the kidneys remove less calcium through the urine. PTH also causes more calcium to be absorbed in your intestines and more calcium to be taken away from your bones.

In a healthy person, a low level of calcium in the blood triggers the release of PTH from the parathyroid glands. This raises the amount of calcium in the blood.

On the other hand, if a person’s level of calcium in the blood is a little high, the parathyroid gland starts to release less PTH. This works to bring the blood calcium back into the normal range.

Types of Hyperparathyroidism

Your clinician may mention that you have either “primary” or “secondary” hyperparathyroidism. This can be important in diagnosis and treatment.

Primary Hyperparathyroidism

Primary hyperparathyroidism refers to a problem in which the parathyroid gland is releasing too much PTH, even though there is enough calcium already in the blood. Most of the time, this is caused by an adenoma (a non-malignant growth) of the parathyroid gland.

Less commonly, primary hyperthyroidism might be caused by:

• Hyperplasia (abnormal enlargement) of the parathyroid glands
• Genetic conditions causing hyperparathyroidism (like multiple endocrine neoplasia)
• A malignant cancer of the parathyroid glands (very rare)

Secondary Hyperparathyroidism

Secondary hyperparathyroidism refers to the normal physiological response in which the parathyroid gland is releasing a higher than normal amount of PTH because calcium in the blood is abnormally low. In other words, the gland is trying to keep the blood calcium at a normal level. That can happen either because a person has a deficiency in vitamin D or is not getting enough calcium through their diet.

For example, this might be caused by:

• Kidney failure (since the kidney helps make usable vitamin D)
• Lack of sun exposure and poor vitamin D intake
• Liver disease
• Poor absorption of calcium from gastrointestinal diseases, like celiac disease

Kidney failure is the most common cause of secondary hyperparathyroidism.

Tertiary hyperparathyroidism

Sometimes, the parathyroid gland keeps releasing too much PTH to the point of raising calcium levels to abnormally higher than normal level in the setting of chronic untreated secondary hyperparathyroidism. In this, overproduction of parathyroid hormone is autonomous and uncontrolled similar to primary hyperparathyroidism.

Diagnosis

Diagnosis of hyperparathyroidism requires that your clinician rule out other possible causes of your symptoms (if present) or of abnormal lab tests. Ultimately, your clinician needs to diagnose not just hyperparathyroidism itself, but its underlying cause.

To understand what is going on, your healthcare provider will need to take your medical history and perform a thorough medical exam. This can help rule out other possible causes and zone in on the exact underlying problem. For example, your healthcare provider will need to make sure that you aren’t taking a medication that might be affecting your calcium.

Laboratory tests are also key in diagnosis. You’ll need to get a blood test for PTH and a blood test for calcium.

Sometimes additional related blood tests are needed, like vitamin D or albumin.

Most of the time, someone with primary hyperparathyroidism will have an elevated PTH as well as elevated calcium. Sometimes, the test for PTH might actually be within the normal range, or just a little bit elevated, along with an elevated calcium test.

That person might still have primary hyperparathyroidism, because their PTH is inappropriately normal. Their PTH should be going down, but it isn’t. In people with primary hyperparathyroidism, PTH isn’t decreasing as it should, in response to elevated calcium.

Conversely, in someone with secondary hyperparathyroidism, PTH is elevated, but the calcium in their blood is normal or low. In this case, the parathyroid glands are working, as they should, to increase the amount of calcium in the blood by releasing PTH. 

Depending on the suspected cause of the hyperparathyroidism, additional tests might be needed as well. These might include:

• Ultrasound of the parathyroid glands (an imaging test)
• Sestamibi scan of the parathyroid glands (another imaging test)
• Basic blood tests for kidney functioning
• Imaging tests of the kidneys
• Genetic testing (if a genetic syndrome is a possibility)
• Bone mineral density test (to check for osteoporosis)

Many people with hyperparathyroidism can be diagnosed by their general healthcare provider. In difficult cases, you might need to be diagnosed or treated by an endocrinologist.

Treatment

Treatment for hyperparathyroidism varies based on the underlying cause and the severity of the condition.

Treating Primary Hyperparathyroidism

Surgery is the most common treatment for primary hyperparathyroidism. The surgeon makes small incisions in your neck and removes only the portions of the parathyroid glands that are affected.

This usually leaves some normal parathyroid tissue in place, so your body can keep making PTH when it needs to. Surgery can sometimes be done as an outpatient procedure, allowing you to go home the same day.

However, not everyone with primary hyperparathyroidism will need surgery. This might be the case if your calcium is only a little elevated and you don’t have any symptoms or signs of long-term complications (like kidney problems or osteoporosis).

If you opt for the watch-and-wait approach, you will need to have repeated blood tests to make sure your calcium still isn’t too high. You may also need other regular follow-up tests (like tests for bone density) to make sure this isn’t becoming a problem.

People who decide not to have surgery have some options for keeping their disease under control. Some healthcare providers prescribe the drug Sensipar (cinacalcet) for primary hyperparathyroidism. This drug may cause the parathyroid glands to release less PTH, and it can lower calcium levels. However, it may not help with bone density problems related to primary hyperparathyroidism.

Other drugs, like bisphosphonates or hormone replacement therapy, may help bones maintain their bone density and prevent complications from osteoporosis.

If you decide not to have surgery, you may need to monitor the amount of calcium in your diet. It’s also important to drink enough fluids, which can help prevent kidney stones. You’ll also want to do other things to help protect your bones, like exercising regularly and not smoking.

Treating Secondary Hyperparathyroidism

The treatment for secondary hyperparathyroidism will vary based on its cause.

If you have secondary hyperparathyroidism related to kidney disease, you may need to receive care from a kidney specialist, a nephrologist. For example, they might recommend Sensipar. You also might need to limit how much protein you eat and take calcium supplements to help address your problem.

Other causes of secondary hyperparathyroidism require different treatments. For example, you might need to avoid foods containing gluten if you have secondary hyperparathyroidism from celiac disease. Or you might need to take vitamin D supplements if you have secondary hyperparathyroidism from a vitamin D deficiency.

A Word From Verywell

It can take a little detective work to figure out what is going on with your hyperparathyroidism, why it is happening, and how you should best address it. Fortunately, most factors that contribute to hyperparathyroidism are treatable.

The more you learn about your condition, the better decisions you will be able to make about the best way to manage it.