What are the common causes of hypercalcemia. How is slightly elevated calcium in blood diagnosed. What are the symptoms of high blood calcium levels. How is hypercalcemia treated. When should you be concerned about elevated calcium levels. Can hypercalcemia be prevented. What are the long-term effects of untreated hypercalcemia.

Understanding Hypercalcemia: When Calcium Levels Rise Above Normal

Hypercalcemia, a condition characterized by elevated levels of calcium in the blood, is a common medical finding that affects millions of Americans annually. While a single instance of high calcium might be due to laboratory error or dehydration, persistent elevation often signals an underlying health issue that requires attention.

The normal range for blood calcium levels typically falls between 8.5 to 10.5 mg/dL (milligrams per deciliter). When levels consistently exceed this range, it’s crucial to investigate the root cause to prevent potential complications.

Prevalence and Significance of Hypercalcemia

How common is hypercalcemia? Studies suggest that about 1 in 500 people may have elevated calcium levels, with the incidence increasing with age. It’s more prevalent in postmenopausal women, affecting approximately 2-3% of this demographic.

Primary Hyperparathyroidism: The Leading Cause of Hypercalcemia

Primary hyperparathyroidism stands out as the most frequent cause of chronically elevated blood calcium levels. This condition occurs when one or more of the parathyroid glands, typically the size of a grain of rice, become overactive and produce excessive amounts of parathyroid hormone (PTH).

The Role of Parathyroid Glands in Calcium Regulation

How do parathyroid glands influence calcium levels? These tiny glands, located behind the thyroid, play a crucial role in maintaining calcium homeostasis. They secrete PTH, which regulates calcium absorption from the intestines, reabsorption in the kidneys, and release from bones. When functioning properly, they help maintain optimal calcium levels for various bodily functions.

In primary hyperparathyroidism, a benign tumor (adenoma) on one of the parathyroid glands often leads to overproduction of PTH. This excess hormone causes more calcium to be released from bones and retained by the kidneys, resulting in elevated blood calcium levels.

Diagnosing Primary Hyperparathyroidism

How is primary hyperparathyroidism diagnosed? The condition is typically identified through blood tests that show both elevated calcium and PTH levels. Classical primary hyperparathyroidism is characterized by calcium levels above 10.5 mg/dL and PTH levels exceeding 65 pg/mL. However, non-classical cases may present with high-normal calcium levels and elevated PTH.

Other Common Causes of Hypercalcemia

While primary hyperparathyroidism is the leading cause, several other conditions can result in elevated blood calcium levels:

• Malignancy (cancer)
• Thiazide diuretics
• Kidney disease
• Familial hypocalciuric hypercalcemia (FHH)
• Milk-alkali syndrome
• Thyroid disorders
• Hypervitaminosis D

Hypercalcemia of Malignancy

Cancer-related hypercalcemia, the second most common cause of elevated calcium levels, occurs in various types of malignancies. How does cancer lead to high calcium levels? Certain tumors can produce substances that mimic PTH or directly stimulate bone breakdown, releasing calcium into the bloodstream.

Types of cancer associated with hypercalcemia include:

• Lung cancer
• Breast cancer
• Esophageal cancer
• Oral and head and neck cancers
• Kidney cancer
• Ovarian cancer
• Uterine and cervical cancers
• Blood cancers (lymphoma and multiple myeloma)

It’s important to note that hypercalcemia of malignancy is relatively uncommon and generally not a concern for most healthy individuals.

Medication-Induced Hypercalcemia

Certain medications, particularly thiazide diuretics, can contribute to elevated calcium levels. These drugs, commonly prescribed for hypertension, affect the kidney’s ability to excrete calcium, leading to its retention in the bloodstream.

Examples of thiazide diuretics include:

• Hydrochlorothiazide (HCTZ)
• Chlorothiazide
• Chlorothalidone
• Indapamide
• Metolazone

Recognizing the Symptoms of Hypercalcemia

Hypercalcemia can manifest with a range of symptoms, varying in severity depending on the calcium level and the rate of increase. Some individuals may remain asymptomatic, especially in mild cases, while others experience significant discomfort.

Common Symptoms of Elevated Calcium Levels

What are the telltale signs of hypercalcemia? Common symptoms include:

• Fatigue and weakness
• Confusion or difficulty concentrating
• Bone pain
• Abdominal pain
• Constipation
• Frequent urination
• Kidney stones
• Nausea and vomiting
• Loss of appetite
• Thirst and increased fluid intake

In severe cases, hypercalcemia can lead to more serious complications such as cardiac arrhythmias, seizures, and coma. It’s crucial to seek medical attention if you experience persistent symptoms or have risk factors for hypercalcemia.

Diagnostic Approaches for Hypercalcemia

Accurately diagnosing hypercalcemia involves a combination of clinical evaluation, laboratory tests, and sometimes imaging studies. The diagnostic process aims to confirm elevated calcium levels and identify the underlying cause.

Blood Tests and Laboratory Analysis

What blood tests are used to diagnose hypercalcemia? Key laboratory assessments include:

• Serum calcium: To measure total calcium levels in the blood
• Ionized calcium: A more accurate measure of biologically active calcium
• Parathyroid hormone (PTH): To assess parathyroid gland function
• Vitamin D levels: To rule out vitamin D toxicity
• Kidney function tests: To evaluate renal health and calcium excretion
• Alkaline phosphatase: An indicator of bone metabolism

Imaging Studies for Hypercalcemia

Depending on the suspected cause, various imaging techniques may be employed:

• Neck ultrasound: To visualize parathyroid glands
• Sestamibi scan: A nuclear medicine test to locate overactive parathyroid glands
• CT scan or MRI: To detect tumors or other structural abnormalities
• Bone density scan: To assess bone health in cases of prolonged hypercalcemia

Treatment Strategies for Hypercalcemia

The treatment of hypercalcemia depends on its severity, underlying cause, and associated symptoms. Management approaches range from addressing the root cause to symptomatic relief and prevention of complications.

Treating Mild to Moderate Hypercalcemia

How is mild hypercalcemia managed? For cases of mild elevation without severe symptoms, treatment may include:

• Increased fluid intake to promote calcium excretion
• Discontinuation of calcium supplements and vitamin D
• Adjustment of medications that may contribute to high calcium levels
• Dietary modifications to reduce calcium intake

Interventions for Severe Hypercalcemia

Severe hypercalcemia, especially when symptomatic, requires more aggressive treatment:

• Intravenous fluids to increase calcium excretion
• Bisphosphonates to inhibit bone resorption
• Calcitonin to lower blood calcium levels rapidly
• Glucocorticoids, particularly in cases of vitamin D toxicity or certain cancers
• Dialysis in severe cases or when kidney function is compromised

Surgical Intervention for Primary Hyperparathyroidism

In cases of primary hyperparathyroidism, surgical removal of the overactive parathyroid gland(s) is often the definitive treatment. This procedure, known as parathyroidectomy, is highly effective in normalizing calcium levels and alleviating symptoms.

Long-Term Management and Monitoring of Hypercalcemia

Effectively managing hypercalcemia often requires ongoing monitoring and follow-up care. The long-term approach depends on the underlying cause and the individual’s overall health status.

Regular Calcium Level Checks

How often should calcium levels be monitored? For individuals with a history of hypercalcemia, regular blood tests are crucial. The frequency of these tests may vary:

• Every 3-6 months for stable, mild hypercalcemia
• More frequently for those undergoing treatment or with fluctuating levels
• Annually for individuals with resolved hypercalcemia to ensure it doesn’t recur

Lifestyle Modifications for Calcium Management

Certain lifestyle changes can help manage calcium levels and prevent complications:

• Maintaining adequate hydration
• Engaging in regular weight-bearing exercise to support bone health
• Limiting dietary calcium intake as advised by a healthcare provider
• Avoiding excessive vitamin D supplementation
• Quitting smoking and limiting alcohol consumption

Monitoring for Complications

Individuals with a history of hypercalcemia should be monitored for potential complications:

• Bone density scans to assess for osteoporosis
• Kidney function tests to detect any renal impairment
• Cardiovascular evaluations to check for heart-related issues
• Neurological assessments if cognitive symptoms were present

Prevention Strategies for Hypercalcemia

While not all cases of hypercalcemia can be prevented, certain measures can reduce the risk or catch the condition early.

Dietary Considerations

How can diet impact calcium levels? While calcium is essential for health, excessive intake can contribute to hypercalcemia in susceptible individuals. Consider these dietary guidelines:

• Consume calcium-rich foods in moderation
• Avoid excessive use of calcium supplements unless prescribed
• Be cautious with fortified foods that may contain added calcium
• Ensure adequate vitamin D intake for proper calcium absorption

Regular Health Check-ups

Routine medical check-ups can help detect hypercalcemia before it becomes symptomatic. These should include:

• Regular blood tests to monitor calcium levels
• Screening for conditions that may predispose to hypercalcemia
• Evaluation of medication side effects that could affect calcium metabolism

Genetic Counseling

For individuals with a family history of hypercalcemia or related disorders, genetic counseling may be beneficial. This can help identify hereditary risks and guide preventive measures.

Emerging Research and Future Directions in Hypercalcemia Management

The field of hypercalcemia research is dynamic, with ongoing studies aimed at improving diagnosis, treatment, and long-term management of the condition.

Advanced Diagnostic Techniques

What new methods are being developed for hypercalcemia diagnosis? Emerging research focuses on:

• Improved imaging techniques for precise localization of parathyroid tumors
• Genetic markers to identify individuals at risk for hereditary forms of hypercalcemia
• Novel biomarkers for early detection of malignancy-associated hypercalcemia

Innovative Treatment Approaches

Ongoing clinical trials are exploring new therapeutic options:

• Targeted therapies for specific forms of hypercalcemia
• Minimally invasive surgical techniques for parathyroid disorders
• Novel pharmacological agents to regulate calcium metabolism

Personalized Medicine in Hypercalcemia Management

The future of hypercalcemia treatment lies in personalized approaches:

• Genetic profiling to tailor treatment strategies
• Individualized dietary and lifestyle recommendations
• Risk stratification models for better management of asymptomatic hypercalcemia

As research progresses, our understanding of hypercalcemia continues to evolve, promising more effective and targeted interventions for individuals affected by this condition. Staying informed about these advancements can help patients and healthcare providers make better decisions in managing hypercalcemia and its associated health impacts.

High Calcium – Endocrine Surgery

High calcium levels or high blood calcium levels

What to do if your blood calcium level is high
The finding of a high blood calcium level is very common, occurring in millions of Americans each year.  Sometimes, this will just be a single event related to a laboratory error or being dehydrated on the day the lab was drawn. 

However, quite frequently a high blood calcium level will mean that there is an important underlying problem.  In general, the first thing to do is re-check the level to confirm it.

Primary hyperparathyroidism is the most common cause of high blood calcium levels >

This is common sense.  For example, if you heard a strange noise in your car, you would certainly listen for it again the next time you drove to double check if it was a real problem, right?  You will see that in these pages we will frequently ask that you use common sense, as using your instincts or “gut feeling” is a good way to avoid being misled by biased or inaccurate information on the web. See Getting started: a word of caution regarding medical information on the internet.

If your blood calcium level is high on more than one occasion, then it is probably time to get more serious about finding out why this is happening.

Causes of high blood calcium levels include:

1. Primary hyperparathyroidism.  This is the most common cause of high blood calcium levels.  People with primary hyperparathyroidism usually have a benign tumor of the parathyroid glands (see What are the parathyroid glands?  Regulation of calcium in the human body) causing excessive amounts of calcium to leave the bone and enter the blood.
2. Malignancy (cancer).  This is the second most common cause of high blood calcium levels, and has nothing to do with the parathyroid glands.  Types of cancer that cause hypercalcemia of malignancy include cancers of the lung, breast, esophagus, mouth, tongue, lip, kidney, ovary, uterus, and cervix.   Blood-borne cancers such as lymphoma and multiple myeloma can also cause high calcium levels.  Thankfully, hypercalcemia of malignancy is uncommon and generally not worth worrying about in most healthy people.  (Really, please don’t worry.  Kindly read on.)
3. Thiazide diuretics.  Thiazide diuretics are a class of medicines that are commonly used to treat hypertension (high blood pressure).  They cause the kidney to “hold on” to calcium, preventing it from exiting in the urine and thereby increasing the blood calcium level slightly.  Examples of thiazide diuretics are: hydrochlorothiazide (HCTZ), chlorothiazide, chlorothalidone, indapamide, and metolazone.
4. Kidney disease, also known as renal failure or chronic renal failure.  High blood calcium levels can be found in people with slow or reduced kidney function, including those on dialysis and those who have had a kidney transplant.
5. Other rare causes, such as:

• Familial hypocalciuric hypercalcemia (FHH), also known as benign familial hypocalciuric hypercalcemia (BFHH) since it is associated with normal health.   This is a rare inherited trait characterized by a slightly high blood calcium level.
• Milk-alkali syndrome, or taking too much calcium by mouth.  Many antacids are calcium salts.  In the past, people with stomach ulcers would treat themselves by drinking lots of milk and taking lots (fistfuls) of calcium salt antacids, thereby raising the blood calcium level.  This is very rare now, since powerful non-calcium-based antacids have become available over the counter.
• Thyroid disease, such as hypothyroidism (too little thyroid hormone) and hyperthyroidism (too much thyroid hormone).  The thyroid gland is a neighbor to the parathyroid glands but has a completely separate function.  The thyroid gland governs metabolism, or how fast the cells in your body work.  In rare cases of severe thyroid disease, blood calcium levels can become imbalanced.
• Hypervitaminosis D, or too much vitamin D (See Vitamin D).  In rare circumstances, people can receive toxic levels of vitamin D leading to high blood calcium.   There have been a few interesting outbreaks of this related to errors in fortifying milk (see references below).
• There are a few more rare causes of high blood calcium levels but we have decided to leave them out because they are so very rare as to barely be worth mentioning.  So please note that this is not a complete list.

Primary hyperparathyroidism is the most common cause of high blood calcium levels (Figure 1). 

This pie chart shows the most common causes of chronically elevated blood calcium levels, meaning when the calcium test is high more than once over several months. 

Classical primary hyperparathyroidism is diagnosed when both the calcium level and the parathyroid hormone (PTH) level are above the normal range (calcium >10.5 mg/dL and PTH >65 pg/mL). 

Non-classical primary hyperparathyroidism is diagnosed when the calcium level is elevated and the PTH level remains higher than it should be, given what the calcium level is (calcium >10. 5 mg/dL and PTH 21-65 pg/mL, this is also known as an inappropriately normal PTH level – see Establishing the diagnosis of primary hyperparathyroidism).  Other causes of high blood calcium are listed above and most commonly refer to hypercalcemia of malignancy (high blood calcium levels due to cancer elsewhere in the body as described above) and use of thiazide diuretics.  Patients with “possible primary hyperparathyroidism” in the pie chart are those in whom the PTH level was never checked; however all of the other causes of high calcium were ruled out.  Please note that renal failure (chronic kidney disease) can also cause high blood calcium levels but those patients were excluded from this analysis.

To summarize, about 90% of patients whose blood calcium levels are found to be high more than once have some form of primary hyperparathyroidism.  If this has happened to you or a family member, you may wish to have the parathyroid hormone (PTH) level checked.  A high or inappropriately normal PTH level will frequently establish the diagnosis of primary hyperparathyroidism (see Establishing the diagnosis of primary hyperparathyroidism).   A low PTH level will suggest other causes of high blood calcium levels.

Where does this information come from?

The pie chart contains data derived from approximately 3.5 million Americans who receive care from a vertically-integrated health maintenance organization in California.  The population studied is similar in size to the population of the state of Ohio.  Through this unique research collaboration, UCLA Endocrine Surgery has been able to study both high blood calcium levels and primary hyperparathyroidism in a completely new way, looking at large, racially diverse populations in great detail with respect to their health outcomes (see How successful is parathyroid surgery?).

References

1. Lafferty FW. Differential diagnosis of hypercalcemia. J Bone Miner Res. 1991 Oct;6 Suppl 2:S51-9; discussion S61. Review. PubMed PMID: 1763670.
2. Stewart AF. Clinical practice. Hypercalcemia associated with cancer. N Engl J Med. 2005 Jan 27;352(4):373-9. Review. PubMed PMID: 15673803.
3. Varghese J, Rich T, Jimenez C. Benign familial hypocalciuric hypercalcemia.Endocr Pract. 2011 Mar-Apr;17 Suppl 1:13-7. Review. PubMed PMID: 21478088.
4. Blank S, Scanlon KS, Sinks TH, Lett S, Falk H. An outbreak of hypervitaminosis D associated with the overfortification of milk from a home-delivery dairy. Am J Public Health. 1995 May;85(5):656-9. PubMed PMID: 7733425; PubMed Central PMCID: PMC1615443.
5. Yeh MW, Haigh PI, Ituarte PH, Liu IL, Zhou H, Nishimoto S, Dell RM, Adams AL. Incidence and prevalence of primary hyperparathyroidism in a racially mixed population. Manuscript in preparation.

What Causes Hypercalcemia? Here Are 6 Known Causes

Written by Keri Wiginton

Medically Reviewed by Poonam Sachdev on April 30, 2022

• Overactive Parathyroid Glands (Hyperparathyroidism)
• Cancer
• Supplements
• Medication
• Genetics
• Less Common Causes
• More

If your doctor tells you that you have hypercalcemia, it means you have too much calcium in your blood. Some medical conditions can cause it. So can the kind of lifestyle you have, your genes, and certain medications.

You may not notice any symptoms if you have a mild case of hypercalcemia. But as your body tries to get rid of the extra calcium, you might pee a lot and get really thirsty. If your calcium levels are very high, you could get nervous system problems, including becoming confused and eventually unconscious.

You’ll usually find out that you have hypercalcemia through a blood test. If you don’t get it treated, high levels of calcium in your blood can lead to bone loss, kidney stones, kidney failure, and heart problems.

Your doctor can help you get your calcium levels back to normal and figure out why they’re out of whack in the first place.

Overactive parathyroid glands are the most common cause of hypercalcemia. When these glands are working right, they release parathyroid hormone (PTH) when your blood calcium levels get low. The release of this hormone helps your body absorb more calcium and lessens the amount you lose when you pee. It also pulls calcium from your bones and puts it into your blood.

But if you have overactive parathyroid glands, your body pumps out more PTH than you need. This can happen if they grow too big or a noncancerous tumor forms on one or more of your glands.

If hyperparathyroidism is the cause of your high calcium, you may also get:

• Depression
• Memory loss
• Heartburn
• Sleep trouble
• Bone and muscle pain
• Fatigue

You may not need treatment if you have mild hypercalcemia. But your doctor will monitor your health. Most likely, they’ll check your blood calcium and blood pressure every 6 months. And they’ll run tests on your kidneys once a year. You may need to get a bone density test every 1-3 years.

They may also tell you to:

• Drink more fluids
• Exercise
• Stop taking thiazide diuretics or lithium

You may need to take drugs called calcimimetics. They lower your PTH levels. In more serious cases, a surgeon may take out your parathyroid gland (or glands).

If your calcium levels are very high, you’ll need to go to the hospital to get fluids and medicine called diuretics through your veins. This can treat hypercalcemia fast.

Around 10%-30% of people with cancer may get hypercalcemia. That’s because cancer can:

• Cause your bones to break down and send calcium into your blood
• Mimic your parathyroid hormone, which triggers the release of calcium from your bones
• Affect your kidneys, which can lower the amount of calcium you get rid of when you pee

The most common cancer types that cause hypercalcemia include:

• Lung cancer
• Kidney cancer
• Breast cancer
• Multiple myeloma (a blood cancer that starts in bone marrow)

Your cancer or the treatment you get for it can share symptoms with hypercalcemia, such as feeling sick or throwing up. If you get dehydrated, your kidneys can’t get rid of calcium very well. Your doctor may give you fluids through your vein.

Hypercalcemia from cancer can be hard to manage. It helps to treat your cancer. But you may need drugs to slow the release of calcium from your bones, including:

• Bisphosphonates — given through your veins
• Denosumab (Prolia, Xgeva) — as an injection

If you take really high doses of vitamin A or D, you may absorb too much calcium. Overuse of calcium-containing antacids can also lead to hypercalcemia.

Your doctor will probably ask you to stop taking these supplements. If your vitamin D levels are really high, you may need to take steroid pills, like prednisone, for a short time.

Blood pressure drugs like thiazide diuretics can lower the amount of calcium that leaves your body when you pee. They may also make your parathyroid problems worse.

More than 20% of people who take lithium get hypercalcemia. Experts aren’t sure why this happens. They think it’s because the drug affects your parathyroid glands and the amount of PTH they make.

Your doctor may switch your medicine. If you need to stay on these drugs, they may give you medication to lower the amount of calcium in your blood.

If you inherit a certain gene, your body misjudges how much calcium is in your blood. You’ll send out more PTH than you need. It happens if you have a condition called familial hypocalciuric hypercalcemia (FHH). But in most cases, you won’t have any symptoms or need treatment.

Your doctor may want to monitor your health. It’s not common, but FHH can cause inflammation in your pancreas or calcium to build up in other parts of your body.

Health conditions. Lung diseases like tuberculosis and sarcoidosis can raise your blood levels of vitamin D. In turn, your gut will absorb more calcium. Paget’s disease and an overactive thyroid are also linked to hypercalcemia.

Inactivity. Your bones release calcium if you don’t put your body weight on them. This can happen if you’re paralyzed or you have another illness that keeps you in bed for a long time. Not getting enough exercise may also make hyperparathyroidism worse.

Serious dehydration. Your kidneys can’t get rid of calcium if you don’t have enough fluid in your body. An easy way to know if you’re dehydrated is to look at your urine. You want it to be light yellow, not a shade of dark orange. You should drink fluids until you’re not thirsty. Call a doctor if you have diarrhea or you throw up for a long time and can’t keep liquids down.

Top Picks

Serum calcium

Calcium is one of the main intracellular cations found mainly in bone tissue. Physiologically, it is active only in the ionized form, in which it is present in large quantities in the blood plasma.

Test method

Colorimetric photometric method.

Units

mmol/l (millimoles per litre).

Russian synonyms

Total calcium.

Synonyms English

Calcium total, Ca.

What biomaterial can be used for research?

Venous, capillary blood.

How to properly prepare for an examination?

• Do not eat for 12 hours before the test.
• Exclude physical and emotional overexertion 30 minutes prior to the study.
• Do not smoke for 30 minutes before the test.

General information about the study

Calcium is one of the most important minerals for humans. It is necessary for the contraction of skeletal muscles and the heart, for the transmission of a nerve impulse, as well as for normal blood clotting (promotes the transition of prothrombin to thrombin), to build the framework of bones and teeth.

Approximately 99% of this mineral is found in the bones and less than 1% circulates in the blood. Almost half of the calcium in the blood is metabolically active (ionized), the rest is bound to proteins (mainly albumin) and anions (lactate, phosphate, bicarbonate, citrate) and is inactive.

Total calcium in the blood is the concentration of its free (ionized) and bound forms. Only free calcium can be used by the body.

Part of the calcium leaves the body every day, being filtered from the blood by the kidneys and excreted in the urine. To maintain equality between the allocation and use of this mineral, it should be about 1 g per day.

When the concentration of calcium in the blood increases, the level of phosphate decreases, when the content of phosphate increases, the proportion of calcium decreases.

Mechanisms of phosphorus-calcium metabolism:

• parathyroid glands with a high phosphate content (at a low level of calcium) secrete parathormone, which destroys bone tissue, thereby increasing the concentration of calcium,
• When calcium levels in the blood are high, the thyroid gland produces calcitonin, which causes calcium to move from the blood to the bones,
• parathyroid hormone activates vitamin D, increasing calcium absorption in the gastrointestinal tract and cation reabsorption in the kidneys.

What is research used for?

First of all, it is worth noting that the results of this test indicate the amount of calcium not in the bones, but in the blood.

• For the diagnosis and control of certain pathological conditions associated with the bone, heart, nervous system, as well as with the kidneys and teeth.
• As part of a biochemical analysis at a routine examination. If the obtained indicators are outside the normal range, it is necessary to do additional tests – for ionized calcium, calcium in the urine, phosphorus, magnesium, vitamin D, parathyroid hormone. Often the balance between these substances is much more important than just their concentrations separately. These indicators help to determine the cause of the disturbed level of calcium in the body: a lack of its intake or excessive excretion by the kidneys.
• In the control of nephrolithiasis, bone disease and neurological disorders.
• For preliminary assessment of calcium metabolism.

When is the examination scheduled?

• During a scheduled preventive medical examination.
• In kidney disease (because calcium levels are low in people with kidney failure).
• In diseases associated with disorders of calcium metabolism, such as pathology of the thyroid gland, small intestine, cancer.
• With certain changes in the electrocardiogram (shortened ST segment with low calcium levels, lengthening of the ST segment and QT interval).
• When a patient has symptoms of elevated calcium levels – hypercalcemia: loss of appetite, nausea, vomiting, lack of stool, abdominal pain, frequent urination, intense thirst, bone pain, fatigue, weakness, headaches, apathy, depression of consciousness up to coma.
• With symptoms of low calcium levels – hypocalcemia: spastic pain in the abdomen, tremor of the fingers, numbness around the mouth, carpopedal spasm, arrhythmias, spasms of the mimic muscle, numbness, tingling, muscle cramps.
• For certain malignant neoplasms (especially lung, breast, brain, throat, kidney and multiple myeloma).
• In case of kidney disease or after transplantation of one of them.
• If it is necessary to monitor the effectiveness of calcium metabolism therapy with calcium and / or vitamin D preparations.

What do the results mean?

Reference values ​​

Usually, the level of total calcium in the blood is measured to assess calcium metabolism. The level of total calcium in the blood is a good indicator of the content of free and bound calcium – each of them accounts for half of the total calcium. However, since about half of the calcium in the blood is associated with proteins, the amount of total calcium changes when protein metabolism is disturbed. In such cases, it is better to measure the level of free (ionized) calcium. The absorption, use and excretion of calcium is regulated by parathyroid hormone and vitamin D by a feedback mechanism. Diseases leading to calcium dysregulation can cause sudden or slow increases in calcium levels, accompanied by symptoms of hypo- and hypercalcemia.

The normal level of total and ionized calcium most likely indicates the absence of disorders of calcium metabolism.

Causes of high calcium levels

An increase in total calcium is hypercalcemia. Its two most common causes are hyperparathyroidism (enlargement of the parathyroid glands) and malignancy.

Hyperparathyroidism is usually caused by a benign tumor of the parathyroid glands.

Cancer formation leads to hypercalcemia after damage to the skeletal system. They secrete a substance similar to parathyroid hormone, and thereby lead to the release of calcium into the bloodstream.

Some other causes of hypercalcemia:

• hyperthyroidism,
• sarcoidosis,
• tuberculosis,
• prolonged immobility,
• vitamin D excess,
• diseases of the blood system (lymphoma, leukemia, multiple myeloma, polycythemia vera),
• kidney transplant,
• dehydration,
• Addison’s disease,
• Paget’s disease.

Causes of low calcium levels

The most common cause of hypocalcemia, a decrease in the amount of total calcium, is a decrease in the content of proteins in the blood, especially albumins. At the same time, only the level of bound calcium is reduced, ionized calcium remains normal and calcium metabolism continues to be regulated by parathyroid hormone and calcitonin.

Some other causes of hypocalcemia:

• hypoparathyroidism (decreased function of the parathyroid glands),
• congenital resistance to the effects of parathyroid hormone (parathyroid hormone has no effect, or it is significantly reduced),
• lack of calcium in the diet,
• magnesium deficiency (hypomagnesemia),
• vitamin D deficiency,
• increasing the concentration of phosphorus,
• sprue, acute pancreatitis, alcoholism (malabsorption of nutrients and, as a result, lack of enzymes and substrates for many types of metabolism),
• chronic renal failure.

What can influence the result?

Some people have high calcium levels due to certain drugs: alkaline antacids, androgens, thiazide diuretics (most common cause), ergocalciferol, lithium salts, progesterone, parathyroid hormone, tamoxifen, vitamins D and A.

Other drugs On the contrary, they can cause a decrease in the concentration of calcium in the blood: gentamicin, calcitonin, anticonvulsants (carbamazepine), glucocorticoids, laxatives, magnesium salts.

In addition, the following factors influence the results of this analysis:

• false values ​​due to dehydration or hyperproteinemia,
• false-low values ​​due to hypervolemia (excessive blood dilution) after intravenous saline.

Important Notes

• Newborns, especially preterm and underweight newborns, have daily blood tests for ionized calcium in the first days of life for early detection of hypocalcemia. It can occur due to underdevelopment of the parathyroid glands, often asymptomatic.
• The concentration of calcium in the blood and urine does not indicate the total content of calcium in the bones – for this there is a special technique for determining bone mineral density, called densitometry.
• Blood calcium levels are usually higher in children and lower in the elderly and pregnant women.
• The level of total calcium in the blood increases with an increase in the concentration of albumin and decreases with its decrease, while the content of ionized calcium does not depend on their concentration.

Also recommended

• Ionized calcium
• Daily urine calcium
• Sulkovich test
• Microalbumin in urine
• Serum magnesium
• Serum albumin
• Total protein in whey
• Vitamin D, 25-hydroxy (calciferol)
• Serum calcitonin
• Thyroid Stimulating Hormone (TSH)
• Thyroxine free (T4 free)
• General thyroxine (T4)
• Triiodothyronine total (T3)
• Triiodothyronine free (T3 free)
• Parathyroid hormone, intact

Who orders the examination?

Therapist, nephrologist, endocrinologist, gastroenterologist, nutritionist, traumatologist.

Endocrinologist told why high blood calcium is dangerous – Moscow 24, 09/13/2022

September 13, 2022, 09:09

Society

The level of calcium in the blood can rise above normal for a variety of reasons. Including with a serious endocrine pathology – hyperparathyroidism. We tell you why it is dangerous, what symptoms it accompanies and how to diagnose it in time.

Frequent pathology

Photo: Moscow 24/Anton Velikzhanin

Calcium is necessary for our body, without it, none of the basic life processes can proceed normally. This microelement is especially important for the health and strength of bones, endocrinologist Marina Berkovskaya told Moscow.

“As a rule, patients are pleased with elevated levels of calcium in the biochemical blood test. They believe that fractures and bone diseases can not be afraid. In fact, the opposite is true,” the doctor said.

The most common cause of elevated blood calcium is primary hyperparathyroidism (excess parathyroid hormone). Among the problems with the endocrine system, it ranks third after diabetes and thyroid disease.

Women suffer from hyperparathyroidism three times more often than men. People over 50 are also at risk. Although pathology can develop at any age.

Marina Berkovskaya

endocrinologist

Excess production of parathormone is bad because it leads to leaching of calcium from the bones, increased excretion with urine, as well as deposition in the internal organs. Therefore, there is a lot of this substance in the blood, vessels, kidneys. In the bones, on the contrary, there is little.

Dangerous complications

Photo: depositphotos/stevanovicigor

In hyperparathyroidism, pathological changes occur primarily in bone tissue and kidneys. If we talk about pronounced manifestations of pathology, then a person may be disturbed by chronic pain in the body, aggravated by pressure, the doctor noted.

Even without injuries, fractures begin to appear, especially in the ribs, pelvic bones and lower extremities. And then they heal long and hard.

Osteoporosis (decrease in bone density) and skeletal deformity develop due to lack of calcium. A “keeled” chest may appear, the shape of the pelvic region may change with the formation of a “duck” gait, and bone tissue growth may begin.

Marina Berkovskaya

endocrinologist

In hyperparathyroidism, excess calcium is removed from the body through the kidneys, so stones form in the excretory tract. As a result, urolithiasis develops. Often it has a aggravated character: colic and the development of renal failure.

In addition, excess calcium in the blood can lead to pathologies of the gastrointestinal tract: peptic ulcer of the stomach or duodenum, cholecystitis (inflammation of the walls of the gallbladder) and pancreatitis (inflammation of the pancreas).

Hyperparathyroidism affects all body systems. Therefore, among the symptoms of the disease may be muscle weakness, arrhythmia, depression, obesity and insulin resistance (impaired metabolic response to insulin).