Hypercalcemia: Causes, Symptoms, and Treatment
Hypercalcemia is a condition in which you have too high a concentration of calcium in your blood. Calcium is essential for the normal function of organs, cells, muscles, and nerves. It’s also important in blood clotting and bone health.
However, too much of it can cause problems. Hypercalcemia makes it hard for the body to carry out its normal functions. Extremely high levels of calcium can be life-threatening.
You might not have any noticeable symptoms if you have mild hypercalcemia. If you have a more serious case, you will typically have signs and symptoms that affect various parts of your body.
Symptoms related to the abdomen include:
- abdominal pain
- decreased appetite
High calcium can affect the electrical system of the heart, causing abnormal heart rhythms.
Calcium levels can affect your muscles, causing twitches, cramps, and weakness.
High calcium levels can affect bones, leading to:
- bone pain
- fractures from disease
Hypercalcemia can also cause neurological symptoms, such as depression, memory loss, and irritability. Severe cases can cause confusion and coma.
If you have cancer and experience any symptoms of hypercalcemia, call your doctor immediately. It’s not uncommon for cancer to cause elevated calcium levels. When this occurs it’s a medical emergency.
Your body uses the interaction between calcium, vitamin D, and parathyroid hormone (PTH) to regulate calcium levels.
PTH helps the body control how much calcium comes into the blood stream from the intestines, kidneys, and bones. Normally, PTH increases when the calcium level in your blood falls and decreases when your calcium level rises.
Your body can also make calcitonin from the thyroid gland when your calcium level gets too high. When you have hypercalcemia, there is excess calcium in your blood stream and your body can’t regulate your calcium level normally.
There are several possible causes of this condition:
The parathyroid glands are four small glands located behind the thyroid gland in the neck. They control the production of the parathyroid hormone, which in turn regulates calcium in the blood.
Hyperparathyroidism occurs when one or more of your parathyroid glands becomes overly active and releases too much PTH. This creates a calcium imbalance that the body cannot correct on its own. This is the leading cause of hypercalcemia, especially in women over 50 years old.
Lung diseases and cancers
Granulomatous diseases, such as tuberculosis and sarcoidosis, are lung diseases that can cause your vitamin D levels to rise. This causes more calcium absorption, which increases the calcium level in your blood.
Some cancers, especially lung cancer, breast cancer, and blood cancers, can raise your risk for hypercalcemia.
Medication side effects
Some medications, particularly diuretics, can produce hypercalcemia. They do this by causing severe fluid diuresis, which is a loss of body water, and an underexcretion of calcium. This leads to an excess concentration of calcium in the blood.
Other drugs, such as lithium, cause more PTH to be released.
Dietary supplements and over-the-counter medications
Taking too much vitamin D or calcium in the form of supplements can raise your calcium level. Excessive use of calcium carbonate, found in common antacids Tums and Rolaids, can also lead to high calcium levels.
High doses of these over-the-counter products are the third most common cause of hypercalcemia in the United States.
This usually leads to mild cases of hypercalcemia. Dehydration causes your calcium level to rise due to the low amount of fluid you have in your blood. However, the severity greatly depends on your kidney function.
In people with chronic kidney disease, the effects of dehydration are greater.
Your doctor can use blood tests to check the calcium level in your blood. Urine tests that measure calcium, protein, and other substances can also be helpful.
If your doctor finds a high calcium level, they’ll order more tests to find out the cause of your condition. Blood and urine tests can help your doctor diagnose hyperparathyroidism and other conditions.
Tests that can allow your doctor to check for evidence of cancer or other diseases that can cause hypercalcemia include:
Treatment options for hypercalcemia depend on the severity of the condition and the underlying cause.
You may not need immediate treatment if you have a mild case of hypercalcemia, depending on the cause. However, you will need to monitor its progress. Finding the underlying cause is important.
The effect that elevated calcium levels have on your body relate not just to the level of calcium present, but how quickly it rises. Therefore, it’s important to stick to your doctor’s recommendations for follow-up.
Even mildly elevated levels of calcium can lead to kidney stones and kidney damage over time.
Moderate to severe cases
You will ly need hospital treatment if you have a moderate to severe case. The goal of treatment is to return your calcium level to normal. Treatment also aims to prevent damage to your bones and kidneys. Common treatment options include the following:
- Calcitonin is a hormone produced in the thyroid gland. It slows down bone loss.
- Intravenous fluids hydrate you and lower calcium levels in the blood.
- Corticosteroids are anti-inflammatory medications. They’re useful in the treatment of too much vitamin D.
- Loop diuretic medications can help your kidneys move fluid and get rid of extra calcium, especially if you have heart failure.
- Intravenous bisphosphonates lower blood calcium levels by regulating bone calcium.
- Dialysis can be performed to rid your blood of extra calcium and waste when you have damaged kidneys. This is usually done if other treatment methods aren’t working.
Depending on your age, kidney function, and bone effects, you might need surgery to remove the abnormal parathyroid glands. This procedure cures most cases of hypercalcemia caused by hyperparathyroidism.
If surgery isn’t an option for you, your doctor may recommend a medication called cinacalcet (Sensipar). This lowers your calcium level by decreasing PTH production. If you have osteoporosis, your doctor might have you take bisphosphonates to lower your risk of fractures.
If you have cancer, your doctor will discuss treatment options with you to help you determine the best ways to treat hypercalcemia.
You might be able to get relief from symptoms through intravenous fluids and medications bisphosphonates. This might make it easier for you to deal with your cancer treatments.
The medication cinacalcet can also be used to treat high calcium levels due to parathyroid cancer. Research suggests it may also have a role in the treatment of hypercalcemia due to other cancers as well.
Hypercalcemia can cause kidney problems, such as kidney stones and kidney failure. Other complications include irregular heartbeats and osteoporosis.
Hypercalcemia can also cause confusion or dementia since calcium helps keep your nervous system functioning properly. Serious cases can lead to a potentially life-threatening coma.
Your long-term outlook will depend on the cause and how severe your condition is. Your doctor can determine the best treatment for you.
Talk to your doctor regularly to stay informed and ask questions. Be sure to keep up with any recommended follow-up tests and appointments.
You can do your part to help protect your kidneys and bones from damage due to hypercalcemia by making healthy lifestyle choices. Make sure you drink plenty of water. This will keep you hydrated, keep blood levels of calcium down, and decrease your risk of developing kidney stones.
Since smoking can speed up bone loss, it’s important to quit as soon as possible. Smoking also causes many other health issues. Quitting smoking can only help your health.
A combination of physical exercises and strength training can keep your bones strong and healthy. Talk to your doctor first to find out what types of exercises are safe for you. This is especially important if you have cancer that affects your bones.
Make sure to follow guidelines for the doses of over-the-counter supplements and medications to decrease the risk of excessive vitamin D and calcium intake.
What precautions should I take if I think I may be at risk for hypercalcemia?
There are several proactive steps you can take. You should stay adequately hydrated by drinking the proper amount of fluids, including water.
You should also consume the proper amount of salt in your diet, which is about 2,000 milligrams of sodium per day for the typical adult.
Finally, talk to your doctor to see whether any of your current prescription or over-the-counter medications might be raising your risk of developing hypercalcemia.
Steve Kim, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
High Calcium Levels or Hypercalcemia
Hypercalcemia is when a person has a higher than usual level of calcium in the blood. About 10% to 20% of people with cancer develop hypercalcemia.
Hypercalcemia can be life threatening and should be treated seriously. Treatment to relieve symptoms and side effects, such as hypercalcemia, is an important part of cancer care. This approach is called supportive or palliative care. Talk with your health care team about any symptoms you experience. This should include any new symptoms or a change in symptoms.
About calcium in the body
Bones have the highest amount of calcium in the body. About 1% of the body’s calcium is in the blood. Calcium is important for many bodily functions. It helps with bone formation and muscle, nerve, and brain function.
The body controls the level of calcium in the blood in many ways. The parathyroid gland, which releases parathyroid hormone, and the kidneys help control blood calcium levels. Vitamin D also helps the body absorb calcium from food. Vitamin D and parathyroid hormone work to adjust calcium levels in the bone and kidneys.
Causes of hypercalcemia
Cancer can cause high levels of blood calcium in several ways. It is important to note that hypercalcemia in people with cancer is not caused by having too much calcium in the diet. This means that eating fewer dairy products and other high-calcium foods does not help to reduce calcium levels in the blood.
The causes of cancer-related hypercalcemia include:
- Bone-related cancers, such as multiple myeloma or leukemia, or cancer that has spread to the bone cause the bone to break down. This releases excess calcium into the blood.
- Some tumors make a protein that acts very similar to parathyroid hormone. This protein causes the bone to release calcium into the blood.
- Some cancers affect how well the kidneys can remove excess calcium from the blood.
- Dehydration caused by nausea and vomiting makes it hard for the kidneys to remove calcium from the blood properly.
- Lack of physical activity can cause bone to break down, releasing calcium into the blood.
Cancers that may cause hypercalcemia include:
- Lung cancer
- Head and neck cancers
- Multiple myeloma
- Kidney cancer
- Breast cancer
- Gastrointestinal cancers
Learn more about specific types of cancer.
Symptoms of hypercalcemia
The symptoms of hypercalcemia often develop slowly. They may be similar to the symptoms of cancer or cancer treatment. The severity of a person’s symptoms is not related to the level of calcium in the blood. Many people have no symptoms. And older patients usually have more symptoms than younger patients.
People with hypercalcemia may have the following symptoms:
- Loss of appetite
- Nausea and vomiting
- Constipation and abdominal pain
- Increased thirst and frequent urination
- Fatigue, weakness, and muscle pain
- Confusion, disorientation, and difficulty thinking
Symptoms of severe hypercalcemia may include:
- Kidney stones, a painful condition in which salt and minerals form solid masses called “stones” in the kidneys or urinary tract
- Irregular heartbeat
- Heart attack
- Loss of consciousness
People with cancer and their families should know and seek treatment for any of these serious symptoms.
Diagnosing and managing hypercalcemia
Your doctor can diagnose hypercalcemia by doing a blood test to check the level of calcium in your body. You may also receive other blood tests to check kidney function.
Once hypercalcemia is diagnosed, your doctor will manage your condition how severe it is.
Mild hypercalcemia. People who have no symptoms receive extra fluids, usually given through a vein. This helps the kidneys remove excess calcium.
Moderate or severe hypercalcemia. This can be managed by:
- Treating the cancer
- Replacing fluids lost through vomiting, frequent urination, or other reasons
- Taking medicines to help stop the breakdown of bone. These include:
- Zoledronic acid (Zometa)
- Pamidronate (Aredia) or Ibandronate (Boniva)
- Denosumab (Prolia, Xgeva)
Taking steroid. Steroids help decrease the breakdown of bone and increase calcium uptake from food. But steroids can somtimes increase the risk of osteoporosis and the breakdown of bone.
Using dialysis for people with kidney failure. Dialysis is a mechanized filtering process that removes excess waste from the blood.
Treating hypercalcemia improves the severity of symptoms and quality of life. In turn, this makes it easier to complete cancer treatment. Yet, sometimes hypercalcemia suggests that a person is approaching the last weeks of life. This may be true when there is no longer an effective treatment for the cancer.
The following tips may help keep hypercalcemia from getting worse:
- Drink fluids
- Control nausea and vomiting
- Walk and be active, which helps prevent bone from breaking down
- Check with your doctor before taking any medications, as some may make hypercalcemia worse
Hypercalcemia is characterized by elevated calcium levels in the blood. It may include symptoms associated with the musculoskeletal, neurological, cardiovascular, and gastrointestinal systems.
Hypercalcemia is often a sign or symptom of other disease occurring within the body. Normal calcium levels range from 8.2-10.2 mg/dL.
Mild hypercalcemia occurs when this level raises to 12mg/dL and severe hypercalcemia is classified as serum calcium at 14mg/dL.
Hypercalcemia is a common medical emergency and between 20-40% of patients suffering from cancer can develop this during the course of their disease. It is considered the most common serious electrolyte presenting in adults with malignancies.
This disorder often occurs in cases of metastatic bone disease with osteolytic lesion, breast cancer and myeloma. This is related to an increase in bone resorption caused by tumor cell production of parathyroid hormone-related protein that stimulates osteoclasts.
It is also associated with primary hyperparathyroidism which occurs in 25 per 100,000 individuals and 75 per 100,000 hospitalized patients. This condition is the most common cause of mild hypercalcemia and can be treated through outpatient care.
More than 50,000 cases occur in the U.S. each year. 
The incidence of hyperparathyroidism is considerably higher in women, thus suggesting women are at greater risk of developing hypercalcemia.
The annual incidence in women older than 65 years is 250 per 100,000, although elevations in calcium levels related to cancer have no sex predominance.
Also, with an increase in age, the incidence of hyperparathyroidism rises just as the rate of malignancy and the malignancy-associated hypercalcemia increases as well.
- Muscle pain, tenderness, and weakness
- Muscle spasms
- Bone pain (worse at night and with weight-bearing)
- Pathological fracture
|Central Nervous System
- Drowsiness, lethargy, coma
- Irritability, personality changes
- Depression, memory loss, difficulty concentrating
- Visual disturbances
- Balance/coordination problems
- Changes in deep tendon reflexes (hypo/hyperreflexia)
- Change in muscle tone ( in individuals with pre-existing neurological condition)
- Positive Babinski and/or clonus reflex
- Changes in bowel/bladder function
- Anorexia (loss of appetite)
- Excessive thirst
- Cardiac arrest
Hypercalcemia can lead to many other complications such as:
- Osteoporosis: if the bones continue to release calcium into the blood, it could lead to this disease.
- Kidney stones: this could be caused by too much calcium accumulation in the urine, leading to crystal formation in the kidneys.
- Kidney failure: Severe hypercalcemia can lead to damage in the kidneys and possibly cause permanent loss of kidney function.
- Nervous system deficits: Severe hypercalcemia can lead to dementia and confusion.
- Arrythmias: Hypercalcemia can affect the electrical impulses of cardiac muscle, causing irregular heartbeats.
- Primary Hyperparathyroidism: This is often associated with hypercalcemia because it causes an increased release of parathyroid hormone (PTH) which raises serum calcium levels.
|| Treatment Effect
|| Side Effects
| Loop Diuretics (ex; furosemide)
|| Flushes out excess calcium from system
|| Frequent urination, arrythmias, electrolyte imbalances, dizziness, muscle cramps/weakness, extreme fatigue, blurred vision, confusion, headache, dehydration, fever, sore throat, cough, skin rash, loss of appetite, nausea, vomiting
| Intravenous Biphosphonates
|| Prevent bone breakdown, reduce bone pain, reduce the number of pathologic fractures
|| Heartburn, headache, constipation, diarrhea, muscle and joint pain
|| Reduce bone reabsorption and slow bone loss
|| Warmth/redness of the skin, itching of the skin, nausea, loss of appetite, stomach pain, vomiting, skin rash, increased urination, eye pain, swelling in the feet, swelling or irritation at injection site (if injection was given)
|| Help to counter the effect of excess Vitamin D
|| Elevated pressure in the eyes, fluid retention that may cause swelling in the legs, increased blood pressure, mood swings, weight gain
|| Remove excess waste and calcium from the bloodstream
|| Hypotension, muscle cramps, itching, difficulty sleeping, anemia, pericarditis, hyperkalemia, infection, depression
Diagnostic Tests/Lab Tests/Lab Values
Hypercalcemia is diagnosed by blood tests revealing increased serum calcium levels. However, other tests may need to be done in order to determine the underlying cause of hypercalcemia. These may include: 
- Chest X-Ray
- CT Scan
These tests may help determine whether you have lung cancer, breast cancer, other malignancies, or sarcoidosis (a granulomatous disease of the lungs). 
Common causes of hypercalcemia include: 
- Overactivity of parathyroid glands
- Cancer-specifically lung and breast cancer as well as multiple myeloma can increase the risk of hypercalcemia. This is considered to be due to the fact that some malignant tumors can produce a protein that acts similar to the parathyroid hormone which stimulates the release of calcium from the bones into the bloodstream.
- Other disease effects-some people with cancer that causes them to spend increased time lying down or in bed may cause bones to release calcium into the blood due to the lack of weight-bearing.
- Medications-Lithium, a drug used to treat bipolar disorder, may increase the release of parathyroid hormone and cause hypercalcemia. Also, Thiazie diuretics can cause elevated calcium levels by decreasing the amount of calcium excreted in the urine.
- Supplements-eating or drinking too much calcium or Vitamin D
- Dehydration-less fluid in your blood causes the calcium levels to increase
As stated in the chart above, hypercalcemia can present with symptoms in multiple systems. Usually, the first signs and symptoms are noticed in the nervous/musculoskeletal system causing some kind of muscle pain, weakness, and/or dysfunction. However, each patient will present differently depending on the severity and organ system involved. 
The primary systems effects and the mechanisms of involvement are described below:
- Increased calcium levels decrease neuromuscular excitability, which leads to hypotonicity in smooth and striated muscle.
- Neuromuscular symptoms include weakness and diminished deep-tendon reflexes.
- Muscle strength is impaired, and respiratory muscular capacity may be decreased.
- Central nervous system impairment may portray as delirium, personality change, cognitive dysfunction, disorientation, hallucinations and delusions.
- Has been documented to increase cerebrospinal fluid protein, which may be associated with headache
- Associated with increased myocardial contractility and irritability.
- Electrocardiographic changes are characterized by slowed conduction, including prolonged P-R interval, widened QRS complex, shortened Q-T interval, shortened or absent S-T segments.
- Incomplete or complete atrioventricular block may develop and progress to complete heart block, a systole, and/or cardiac arrest.
- Symptoms related to the depressive action of hypercalcemia on the autonomic nervous system, resulting smooth-muscle hypotonicity.
- Increased gastric acid secretion often accompanies hypercalcemia.
- Anorexia, nausea, and vomiting are made worse by increased gastric residual volume.
- Constipation is worse due to dehydration associated with hypercalcemia.
- Abdominal pain may progress to obstipation (can be confused with acute abdominal obstruction).
- Loss of urinary concentrating ability and polyuria due to tubular defect in the kidney.
- Decreased fluid intake and polyuria lead to symptoms associated with dehydration.
- Decreased reabsorption of sodium, magnesium, and potassium occur as a result of salt and water depletion
- Renal insufficiency may occur as a result of diminished glomerular filtration.
- Hypercalcemia of malignancy (multiple myeloma) can result from osteolytic metastases or humerally mediated bone resorption.
- Secondary fractures, skeletal deformities, and/or pain may be symptoms present.
Medical Management (current best evidence)
Mild Hypercalcemia (defined as corrected total serum calcium level lower than 12 mg/dL (
Hypercalcemia: The Definition and Causes of Hypercalcemia
Hypercalcemia is the medical word for “high blood calcium.” It is almost never normal and almost always requires further testing and often treatment of the underlying problem to bring the high blood calcium back into the normal range.
Hypercalcemia should not be ignored or just “monitored” because it typically means bad things are on the way. Calcium is one of the most important minerals in your body that serves many functions and thus it needs to be kept in a very tight range – you don’t want too little OR too much of it.
Because a normal blood calcium is required for good health, the measurement of blood calcium levels is part of the standard blood tests when patients have an annual checkup, or go to the doctor (or emergency room) when feeling ill.
When your doctor orders routine blood tests, calcium is usually part of the standard panel (it’s in the Basic Metabolic Panel, one of the most common blood tests).
What Physicians Need to Know About Hypercalcemia
Many physicians end up on this page after searching “hypercalcemia” online. The most important thing for doctors to know is that hypercalcemia is almost never caused by cancer in the ambulatory patient.
If you have a patient in your office that isn't dying of cancer (that you have already known about for months or years), then the hypercalcemia is almost always due (over 99%) to primary hyperparathyroidism.
Cancers do not present with high calcium–in fact, very few cancers are ever associated with high blood calcium, and when they are, the patient is already in the hospital (in the ICU?) and end-of-life preparations have been ongoing for months.
An ambulatory patient with hypercalcemia does NOT need any form of cancer work up. They do not need a CT scan, MRI scan, PET scan or even a chest-x-ray to “rule out” cancer.
Virtually every patient in every doctors office (even an oncologist's office) with hypercalcemia should be presumed to have hyperparathyroidism and tests run to confirm this diagnosis outlined on our Parathyroid Advanced Diagnosis page. There is a lot of very valuable information for doctors and patients further down on this current page, so keep reading.
Hypercalcemia vs. Normal Calcium Levels Will Change According to your Age
Most labs will give a normal calcium range from about 8.8 to 10.5 mg/dl. But this doesn’t mean that this is a normal range for everyone – it depends on your age (we have a calculator for you further down on this page). A value of 10.5 in a teenager is perfectly normal, but 10.
5 in adult over age 35 is too high – this is hypercalcemia. The graph below shows the normal range of blood calcium in green and you can see that it changes as we get older. Teenagers and young adults can have normal calcium levels up into the mid 10s (mg/dl).
But adults over the age of about 35 should have lower calcium levels, not going above 10.0 mg/dl. (NOTE: Canadian and European version of this graph is at the bottom of this page). Adult calcium levels usually range somewhere between 9.0 and 10.0 mg/dl, which is why we to say that “adults live in the 9s”.
It is typically not normal for adults to have frequent or persistent calcium levels in the 10s.
Hypercalcemia is almost always caused by Hyperparathyroidism
Hypercalcemia can be caused by only a few things. Often people are told that hypercalcemia is caused by cancer, but this is extremely rare.
We have an entire page on the different causes of hypercalcemia (including different types of cancer) that you can read (click here), but it is important to understand that over 99% of cases of hypercalcemia are caused by a parathyroid gland tumor; a disease called hyperparathyroidism.
People with parathyroid disease (hyperparathyroidism) almost always have hypercalcemia: they have blood calcium levels in the 10s or higher.
The graph below shows highest calcium levels for over 20,000 consecutive adults with parathyroid disease who were treated at our center.
About half of patients with hyperparathyroidism (a parathyroid tumor causing hypercalcemia) have calcium levels between 10.0 and 11.0 mg/dl, and half have calcium levels above 11.0 mg/dl.
What’s wrong with hypercalcemia? Don’t I need lots of calcium for my bones?
Hypercalcemia is not good, and actually, can be quite bad for you. It is now known that even mild elevations in blood calcium (mild hypercalcemia) can be very detrimental to your overall health over time. The high blood calcium can cause many problems with many different parts of the body, but it also makes people feel bad.
Hypercalcemia will cause symptoms in almost everyone. The most common symptoms of hypercalcemia are chronic fatigue, lack of energy, loss of interest in things you used to enjoy, “brain fog” or difficulty concentrating, and trouble with sleep.
It also causes kidney stones, heartburn or gastric reflux (GERD), headaches, depression, high blood pressure, palpitations or cardiac arrhythmias, and chronic kidney failure. And because calcium is coming your bones, it causes a loss in bone density, leading to osteopenia and osteoporosis. Hypercalcemia can make you miserable.
The most popular page of this large website is the Symptoms of Hyperparathyroidism page.
Here is the most important thing to know about the symptoms of hypercalcemia: they are NOT correlated with how high the calcium is. That is, someone with only a slightly high calcium can feel just as bad as someone with a much higher blood calcium level, and they will have the same chances of getting all of the complications.
Some doctors out there do not know this! In medical school they were taught that the calcium level determined how bad the disease was, so a mild hypercalcemia meant a mild disease and worse hypercalcemia meant worse problems. In treating tens of thousands of patients with hyperparathyroidism, we know this is not true.
Mild hypercalcemia is just as bad as more pronounced hypercalcemia. This is illustrated very nicely in the graph below where we looked at over 20,000 patients operated on for hyperparathyroidism and hypercalcemia.
It shows that people with only mild elevations of blood calcium (between 10 and 11 mg/dl) have just as many symptoms and complications from the high calcium as people with much higher calcium levels (above 11.1 mg/dl).
Hypercalcemia Causes: An Overview
Hypercalcemia is almost always caused by a parathyroid tumor (called primary hyperparathyroidism). Parathyroid glands are tiny endocrine glands in your neck, next to your thyroid. You have four of them, and the only thing they do is control blood calcium levels.
They do this by making parathyroid hormone (PTH), which raises the blood calcium level by taking calcium your bones. A normal parathyroid gland will produce just enough PTH to keep your blood calcium level in normal range. A parathyroid tumor will produce more PTH than necessary, which will push the calcium level up.
Parathyroid tumors are benign in almost every case, so you don’t need to worry about cancer.
If you have been told that you have hypercalcemia, the overwhelming odds are that you have a parathyroid tumor. There are a few other causes of hypercalcemia, which you can read about on our page on Causes of High Blood Calcium, but they are much, much less common. Hypercalcemia is almost always due to a parathyroid problem.
Hypercalcemia is diagnosed by a blood calcium test. If the calcium is high, then you have hypercalcemia. The next step is to figure out what the cause of hypercalemia is.
Since almost all hypercalcemia is caused by a parathyroid problem, the obvious next step is to measure the amount of parathyroid hormone (PTH) in the blood. This is a simple blood test. If you have hypercalcemia and a PTH level that is in the high or normal range, then you have a parathyroid tumor.
Note that a high PTH level isn’t required to make the diagnosis of hyperparathyroidism as the cause of the hypercalcemia—but the PTH level can’t be low. Scans, x-rays, and imaging tests are NOT to be used to diagnose hyperparathyroidism — it is diagnosed on blood tests alone.
We have two very excellent pages on the diagnosis of hyperparathyroidism: 1) The Diagnosis of Hyperparathyroidism, and 2) Advanced Diagnosis Tricks for Hyperparathyroidism.
Since hypercalcemia is almost always due to a parathyroid tumor, and there are no medications that can treat this – the treatment is to remove the tumor. Fortunately, parathyroid surgery is curative and can be done in a minimally invasive outpatient operation. Removing the parathyroid tumor is the only way to cure almost every case of hypercalcemia.
Everyone with primary hyperparathyroidism is a candidate for this operation. As mentioned above, even “mild” hypercalcemia will lead to problems if left untreated. There is no reason to wait for these complications to occur. Get the tumor your neck before it does damage! Read some of our patient testimonials to learn about how this simple operation can be life-changing.
Hypercalcemia on the Electrocardiogram
Hypercalcemia is defined as an increase in the serum calcium level in the plasma higher than 10.4 mg/dL (2.60 mmol/L or 5.2 mEq/L).
Hypercalcemia may cause electrocardiogram changes, predominantly in the duration of the ST segment and the QT interval, due to alterations in the duration of the plateau of the action potential.
Almost all the calcium in the body (99%) is stored in the bone, with only about 1% in the extracellular fluid and 0.1% in the intracellular fluid 1.
About 50% of the total calcium in the plasma exists in the ionized form, which is the form that has biological activity at cell membranes.
The remainder is either bound to the plasma proteins (about 40%) or complexed in the non-ionized form with anions such as phosphate and citrate (about 10%) 1.
Changes in extracellular calcium concentration have a profound effect on the duration of the plateau (phase 2) of the action potential. The duration of the plateau increases at low calcium concentrations and shortens at high calcium concentrations 2.
Because the plateau duration of the ventricular action potential determines the duration of the ST segment, the changes in calcium concentration predominantly affect the duration of the ST segment and thereby the duration of the QT interval 2.
Causes of Hypercalcemia
Normal serum calcium levels are between 8.8 mg/dL (2.1 mmol/L) and 10.4 mg/dL (2.6 mmol/L). Levels above 10.4 mg/dL (2.6 mmol/L ) indicate hypercalcemia.
- Mild hypercalcemia: serum calcium between 10.4 mg/dL (2.60 mmol/L) and 11.5 mg/dL (2.88 mmol/L).
- Moderate hypercalcemia: serum calcium between 11.5 mg/dL (2.88 mmol/L) and 18 mg/dL (4.51 mmol/L).
- Severe Hypercalcemia: serum calcium > 18 mg/dL (4.50 mmol/L)
In hypercalcemia, the ST segment is short or absent and the duration of the corrected QT interval (QTc) is decreased 2.
The QTc interval is inversely proportional to the serum calcium level up to 16 mg/dL(4 mmol/L) 3.
With marked hypercalcemia, the T wave appears to take off right from the end of the QRS complex 4.
No changes in the QRS and PR durations have been reported.
Hypercalcemia usually does not alter the morphology of the P waves or T waves, but a slight, statistically significant increase in T wave duration was reported.
The U wave amplitude is either normal or increased.
EKG of hypercalcemia: short ST segment and short QTc interval (QTc 285 ms).
In the presence of hypercalcemia associated with hypokalemia, a short QT interval with increased U wave amplitude results in a distinct pattern, most often seen in patients with multiple myeloma.
In severe hypercalcemia, Osborn waves (J waves) may be seen. Severe hypercalcemia may also mimic a ST-segment elevation myocardial infarction on the EKG.
Cardiac arrhythmias are uncommon in patients with hypercalcemia. However, sudden death during hyperparathyroid crisis and other conditions associated with severe hypercalcemia may be caused by ventricular fibrillation 2.
Second or third degree AV blocks have been also reported in patients with severe hypercalcemia 2.
Treatment of hypercalcemia depends on the severity of symptoms and the underlying cause.
Asymptomatic or mildly symptomatic patients with mild or chronic moderate hypercalcemia may not require immediate treatment 5.
Patients with hypercalcemia of malignancy are typically symptomatic and have markedly elevated calcium levels. These patients will generally need to be managed with urgency, and hypercalcemia of malignancy in many cases represents an oncologic emergency 5.
Patients with asymptomatic or mildly symptomatic hypercalcemia do not require immediate treatment. Adequate hydration (at least 1.5 to 2 liters of water per day) is recommended.
However, they should be advised to avoid factors that can aggravate hypercalcemia, including thiazide diuretics and lithium carbonate therapy, volume depletion, prolonged bed rest, and a high calcium diet.
Asymptomatic or mildly symptomatic individuals with chronic moderate hypercalcemia may not require immediate therapy.
However, an acute rise to these levels may cause gastrointestinal side effects and changes in sensorium, which requires treatment as described for severe hypercalcemia 5.
Patients with severe hypercalcemia are dehydrated by default and require saline hydration as initial therapy 6.
For immediate short-term management of severe hypercalcemia who are also symptomatic, administration of calcitonin should be considered 5 6.
For longer-term control of hypercalcemia due to excessive bone resorption, is recommend the addition of a bisphosphonate. Denosumab, human monoclonal antibody, is an option for patients with hypercalcemia that is refractory to bisphosphonates 5 6.
Glucocorticoids are effective in treating hypercalcemia due to some lymphomas, sarcoid, or other granulomatous diseases.
Dialysis is considered treatments of last resort. It may be indicated in patients with severe malignancy-associated hypercalcemia and renal insufficiency or heart failure, in whom hydration cannot be safely administered.
Patients with hypercalcemia typically have a shortened ST segment and a shortened QT interval on the electrocardiogram.
The QTc interval usually is inversely proportional to the serum calcium level, and with marked hypercalcemia, the T wave appears to take off right from the end of the QRS complex.
Management of hypercalcemia includes IV hydration, calcitonin, bisphosphonates, denosumab, and prednisone. Patients with advanced kidney disease and refractory severe hypercalcemia should be considered for dialysis.
We hope this article help you to identify hypercalcemia on the electrocardiogram
Related articles: Hypocalcemia, hyperkalemia, ST segment.
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