• Hyperparathyroidism

    High-Calcium Consequences


High-Calcium Consequences

Hyperparathyroidism is a condition where one or more of the four parathyroid glands in your neck become overactive, releasing too much parathyroid hormone (PTH) into the bloodstream.

Though the condition can have very serious health consequences if left untreated, the early symptoms are subtle. A slightly high calcium level in a routine blood test is usually the first sign that something is wrong. A follow-up test of PTH levels can confirm the diagnosis. We can then use various scanning techniques to identify the overactive gland.

Fortunately, there is a highly effective cure for hyperparathyroidism: minimally invasive surgery to remove the overactive gland. The remaining healthy parathyroid glands can then quickly restore good calcium balance.

Subtle Symptoms and Critical Consequences

The health consequences of untreated hyperparathyroidism can be severe, even life-threatening. But the early symptoms are often subtle or even nonexistent. You may feel completely fine. The only warning sign may be a slightly high calcium level in a routine blood test during your annual physical.

However, even in the early stages of the disease, you may notice some symptoms. You may start feeling tired all the time, or you may experience mild to moderate depression. Your blood pressure may go up, and you may develop osteopenia or osteoporosis. You may suffer from constipation or become prone to kidney stones.

There are, of course, many other conditions that can cause these same symptoms. This is one of the reasons hyperparathyroidism is often not diagnosed as early as it should be. Left untreated, however, this condition can become a real threat to your health. High blood pressure can worsen to the point of heart failure. The constant demands on your kidneys can lead to kidney failure. Your bones can become dangerously brittle.  You can have increased calcium deposits lining critical arteries in your heart or your brain.

Fortunately, today we can diagnose hyperparathyroidism early and accurately. And we can cure it long before it becomes a danger to your good health. If your latest blood test showed a high calcium level, please get tested for hyperparathyroidism. With an early diagnosis, this condition can be a minor and temporary inconvenience rather than a serious threat to your health.

When we catch hyperparathyroidism early, we can cure it before it damages your body. If you have a high calcium level, take it seriously and get tested.

Dr. John S. Kennedy

High Calcium and PTH: A Definitive Diagnosis

For most people, the first sign that you might have hyperparathyroidism is a high total calcium level on a routine blood test, perhaps one you had done for your annual physical. A high calcium level is not, on its own, enough to diagnose hyperparathyroidism. It should, however, always raise the question of hyperparathyroidism and prompt a follow-up test.

What counts as “high” calcium? Well, it varies slightly by age. Teenagers and young adults naturally have higher calcium levels in their blood. They need it to build those fast-growing bones and muscles. So a somewhat higher calcium level in a teenager might be perfectly normal but much too high for an adult. The normal range for adults is between about 9 and 10 mg/dL. A calcium level as low as 10.2 in a mature adult should be taken seriously. 10.3 or 10.4? You should definitely get tested.

The follow-up is simple: a test of the parathyroid hormone (PTH) level in your blood. If you have both high calcium and high PTH, the diagnosis is clear: you have hyperparathyroidism. Once we find the overactive parathyroid gland, we know how to cure it.

If your PTH level is in the normal range, diagnosis is slightly more complicated. With healthy parathyroids, a higher calcium level should lead to a lower PTH level. So a PTH level in the normal range can still be too high when we consider it alongside your high calcium level. If it is, we again can diagnose hyperparathyroidism. And again, we know how to cure it.

If, however, your PTH level is appropriately balanced to your high calcium level, then something else is going on. You have, at least, now eliminated one likely cause of your high calcium.

Some doctors will ignore a calcium level that is ‘just a little’ high, but even a slightly high calcium level can be an early sign of hyperparathyroidism. If your blood test shows high calcium, you should get tested for high PTH.

Dr. John S. Kennedy

Finding the Overactive Gland

Once you have a diagnosis of hyperparathyroidism, the next question becomes: which gland? You have four parathyroid glands in your neck, but hyperparathyroidism is usually caused by one overactive gland, though more than one overactive gland is possible.

Before the days of minimally invasive surgery, surgeons might visually identify the overactive gland during surgery. Today, however, we can use minimally invasive techniques to remove the gland through a tiny little cut in the neck. With this surgical technique, you’ll recover from surgery much more quickly. The precision this method requires, however, means we need some advanced help to find the problem parathyroid.

Many different tests can be used to locate an overactive parathyroid gland, including CT scans, SPECT scans, CT angiography, and venous sampling. However, in most cases, two tests, paired together, work best: an ultrasound and a sestamibi scan.

When to Scan

Ultrasounds, sestamibi scans, and the other scans discussed here are all pre-operative tests, not diagnostic tests. In other words, we don’t need these tests to diagnose hyperparathyroidism, and there’s no need for you to get them before your first surgical consultation. Dr. Kennedy uses these scans to plan and guide him during your surgery. He will perform your ultrasound himself, and your sestamibi scan is most useful immediately before your surgery. Don’t waste time and money on tests that we’ll only have to repeat as we prepare for your surgery.


Yes, the same ultrasound that checks in on the health of developing babies can help us find a problem parathyroid. Healthy parathyroid glands are too small to show up on ultrasound. Overactive glands, however, are enlarged. To the trained eye of a parathyroid expert, they show up as dark, somewhat triangular spots just behind the thyroid gland.

The ultrasound also gives us a look at your thyroid and the rest of your neck. If there are any abnormalities to address or work around, we want to know about them before we begin surgery.

Dr. Kennedy performs the ultrasound himself, usually during your first consultation. Hyperparathyroid surgery is a highly specialized field, and many ultrasound technicians have little experience in locating overactive parathyroids. Dr. Kennedy’s long experience in the field allows him to identify the enlarged gland or glands, and to begin visualizing the necessary surgery.

Sestamibi Scan

In a sestamibi scan, we give you a short-lived radioisotope intravenously, right before your surgery. Overactive parathyroid glands absorb much more of the isotope than healthy parathyroids.

The radioisotope is also absorbed by other active organs, including the heart, liver, salivary glands, and thyroid glands. The parathyroid glands are generally right behind the thyroid glands. To the inexperienced eye, the scan may appear to show only the butterfly shape of the thyroids.

However, a skilled parathyroid expert can spot an overactive parathyroid as an area of greater intensity within the wings of the thyroid butterfly. This allows us to pinpoint the location of the problem parathyroid.

The test does have some limitations. Most importantly, the sestamibi scan is best at finding a single overactive parathyroid. Some people with hyperparathyroidism have more than one overactive gland. The sestamibi scan will often only identify the most active gland, missing any additional problem glands. That’s why we test all four glands during surgery.

Other Tests

In most cases, the sestamibi scan and the ultrasound, together, are all we need to identify the gland or glands to remove. There are, however, some other tests we sometimes use when needed:

  • A CT scan, which creates a three dimensional image using X-rays, can sometimes give a more detailed picture of an overactive parathyroid, but it is rarely necessary.
  • A SPECT scan (single photon emission computed tomography) uses gamma rays to create a three-dimensional image of the neck. Though popular at some parathyroid clinics, the images are low resolution and rarely add any value to what the sestamibi scan already reveals.
  • CT angiography uses intravenous contrast paired with a CT scan to look for abnormalities in the parathyroid glands. For a first-time — and usually last-time — parathyroid surgery, this test is almost never necessary. It is a useful test in those rare cases where removal of an overactive parathyroid fails to cure hyperparathyroidism.
  • Venous sampling is a sophisticated test that threads a tiny catheter through your veins up into your neck. We then sample the PTH levels in different areas of your neck to find where the excess PTH is coming from. The test is highly accurate but only necessary in very unusual circumstances where the sestamibi scan and ultrasound cannot find the overactive gland.

A test is not more valuable simply because it’s more expensive. An ultrasound and a sestamibi scan are usually all I need to find an overactive parathyroid. If you go to some other parathyroid surgeon who orders additional scans, ask them to explain why they think these tests are needed.

Dr. John S. Kennedy