What are the main causes of hypercalcemia. How can slightly elevated calcium levels in blood be diagnosed. What are the common symptoms of high blood calcium. How is hypercalcemia treated. When should you be concerned about elevated calcium levels.

What is Hypercalcemia and Why Does It Occur?

Hypercalcemia is a condition characterized by elevated levels of calcium in the blood. While calcium is essential for various bodily functions, including bone health and muscle contraction, having too much calcium circulating in the bloodstream can lead to a range of health issues. Understanding the causes, symptoms, and management of hypercalcemia is crucial for maintaining overall health and preventing potential complications.

Common Causes of Hypercalcemia

There are several factors that can contribute to the development of hypercalcemia:

• Primary hyperparathyroidism
• Cancer (hypercalcemia of malignancy)
• Certain medications, particularly thiazide diuretics
• Kidney disease
• Genetic disorders
• Excessive calcium or vitamin D intake
• Thyroid disorders

Primary hyperparathyroidism is the most prevalent cause of chronic hypercalcemia, accounting for a significant portion of cases. This condition occurs when one or more of the parathyroid glands produce excessive amounts of parathyroid hormone (PTH), leading to increased calcium absorption and release from bones.

Recognizing the Symptoms of High Blood Calcium

Identifying the symptoms of hypercalcemia is crucial for early detection and treatment. However, it’s important to note that mild cases may not present any noticeable symptoms. As calcium levels rise, individuals may experience:

• Fatigue and weakness
• Confusion or difficulty concentrating
• Bone pain
• Abdominal pain or constipation
• Increased thirst and frequent urination
• Nausea and vomiting
• Muscle aches and twitches
• Depression or mood changes

Is there a correlation between symptom severity and calcium levels? Generally, the higher the calcium levels, the more pronounced the symptoms. However, individual responses can vary, and some people may experience significant symptoms even with mildly elevated calcium levels.

Diagnosing Hypercalcemia: Beyond the Initial Blood Test

Diagnosing hypercalcemia typically begins with a routine blood test that reveals elevated calcium levels. However, a single high reading doesn’t necessarily confirm the condition. To ensure accuracy and rule out temporary fluctuations, healthcare providers often recommend the following steps:

1. Repeat blood calcium test to confirm elevated levels
2. Check parathyroid hormone (PTH) levels
3. Assess vitamin D levels
4. Evaluate kidney function
5. Consider additional tests based on suspected underlying causes

How soon should a follow-up test be conducted after an initial high calcium reading? Typically, healthcare providers recommend repeating the blood calcium test within a few weeks to confirm persistent elevation. This helps distinguish between temporary fluctuations and chronic hypercalcemia.

Primary Hyperparathyroidism: The Leading Cause of Hypercalcemia

Primary hyperparathyroidism (PHPT) is the most common cause of chronic hypercalcemia, accounting for approximately 80-85% of cases. This condition occurs when one or more of the parathyroid glands, typically due to a benign tumor called an adenoma, produce excessive amounts of parathyroid hormone (PTH).

Identifying Primary Hyperparathyroidism

Diagnosis of PHPT involves a combination of blood tests and imaging studies:

• Elevated serum calcium levels (typically above 10.5 mg/dL)
• Increased PTH levels (above 65 pg/mL)
• Normal or elevated vitamin D levels
• Imaging studies (e.g., ultrasound, sestamibi scan) to locate enlarged parathyroid glands

Can primary hyperparathyroidism resolve on its own? In most cases, PHPT is a progressive condition that requires medical intervention, typically surgical removal of the affected parathyroid gland(s). Spontaneous resolution is rare, and ongoing monitoring is essential for those who don’t undergo immediate treatment.

Hypercalcemia of Malignancy: When Cancer Affects Calcium Levels

Hypercalcemia of malignancy is the second most common cause of elevated blood calcium levels, occurring in approximately 10-20% of cancer patients. This condition can develop through various mechanisms, including:

• Tumor production of PTH-related protein (PTHrP)
• Osteolytic metastases releasing calcium from bones
• Tumor-induced production of calcitriol (active vitamin D)
• Ectopic production of PTH by certain tumors

Which types of cancer are most commonly associated with hypercalcemia? Lung cancer, breast cancer, multiple myeloma, and renal cell carcinoma are among the malignancies frequently linked to hypercalcemia. However, it’s important to note that hypercalcemia can occur with various cancer types.

Differentiating Hypercalcemia of Malignancy from Other Causes

Distinguishing hypercalcemia of malignancy from other causes, particularly primary hyperparathyroidism, is crucial for appropriate treatment. Key factors in the differential diagnosis include:

• Rate of calcium level increase (often more rapid in malignancy)
• Presence of other cancer-related symptoms
• PTH levels (typically suppressed in hypercalcemia of malignancy)
• PTHrP levels (elevated in many cases of malignancy-associated hypercalcemia)

Medication-Induced Hypercalcemia: The Role of Thiazide Diuretics

Certain medications, particularly thiazide diuretics, can contribute to the development of hypercalcemia. Thiazide diuretics are commonly prescribed for hypertension management and work by increasing calcium reabsorption in the kidneys, potentially leading to elevated blood calcium levels.

Common Thiazide Diuretics Associated with Hypercalcemia

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

How significant is the risk of hypercalcemia with thiazide diuretic use? While thiazide diuretics can cause a mild increase in blood calcium levels, clinically significant hypercalcemia is relatively uncommon. However, individuals with underlying calcium metabolism disorders may be more susceptible to thiazide-induced hypercalcemia.

Managing Medication-Induced Hypercalcemia

When hypercalcemia is suspected to be medication-induced, healthcare providers may consider the following approaches:

1. Reassessing the need for the medication
2. Adjusting the dosage
3. Switching to an alternative medication
4. Monitoring calcium levels closely
5. Addressing any underlying calcium metabolism disorders

Kidney Disease and Hypercalcemia: A Complex Relationship

Chronic kidney disease (CKD) can significantly impact calcium homeostasis, potentially leading to hypercalcemia. The relationship between kidney function and calcium levels is complex, involving various factors:

• Reduced calcium excretion due to impaired kidney function
• Secondary hyperparathyroidism developing as a compensatory mechanism
• Altered vitamin D metabolism affecting calcium absorption
• Potential overuse of calcium-based phosphate binders in CKD management

Does hypercalcemia occur in all stages of chronic kidney disease? Hypercalcemia is more commonly observed in advanced stages of CKD, particularly in patients on dialysis or those who have undergone kidney transplantation. However, calcium imbalances can occur at various stages of kidney disease, necessitating regular monitoring.

Managing Hypercalcemia in Kidney Disease Patients

Addressing hypercalcemia in the context of kidney disease requires a multifaceted approach:

1. Optimizing dialysis treatment (for those on dialysis)
2. Adjusting calcium and vitamin D supplementation
3. Managing secondary hyperparathyroidism
4. Considering calcimimetic medications
5. Evaluating the need for parathyroidectomy in severe cases

Rare Causes of Hypercalcemia: Beyond the Common Culprits

While primary hyperparathyroidism and malignancy account for the majority of hypercalcemia cases, several less common causes deserve attention:

Familial Hypocalciuric Hypercalcemia (FHH)

FHH is a rare inherited condition characterized by mildly elevated calcium levels and low urinary calcium excretion. Unlike primary hyperparathyroidism, FHH typically doesn’t require treatment and is associated with normal health outcomes.

Milk-Alkali Syndrome

This condition results from excessive intake of calcium and absorbable alkali, often from antacids or calcium supplements. While less common today due to improved antacid formulations, it remains a potential cause of hypercalcemia.

Thyroid Disorders

Both hypothyroidism and hyperthyroidism can affect calcium metabolism, potentially leading to hypercalcemia in severe cases.

Hypervitaminosis D

Excessive vitamin D intake or production can lead to increased calcium absorption and hypercalcemia. This can occur due to supplementation errors or certain medical conditions.

How can rare causes of hypercalcemia be identified? Diagnosing rare causes of hypercalcemia often requires a comprehensive evaluation, including detailed medical history, family history, medication review, and specialized laboratory tests. In some cases, genetic testing may be necessary to confirm inherited disorders affecting calcium metabolism.

Treatment Approaches for Hypercalcemia: Tailoring Care to the Cause

Managing hypercalcemia involves addressing the underlying cause while simultaneously controlling calcium levels. Treatment strategies vary depending on the severity of hypercalcemia and its etiology:

Mild Hypercalcemia

• Increasing fluid intake
• Limiting dietary calcium and vitamin D
• Discontinuing or adjusting medications that may contribute to hypercalcemia
• Regular monitoring of calcium levels

Moderate to Severe Hypercalcemia

• Intravenous fluid administration
• Diuretic therapy (e.g., loop diuretics) to enhance calcium excretion
• Bisphosphonates to inhibit bone resorption
• Calcitonin to reduce bone calcium release and increase renal calcium excretion
• Dialysis in severe cases or when other treatments are ineffective

Cause-Specific Treatments

• Surgical removal of parathyroid adenomas in primary hyperparathyroidism
• Cancer-directed therapies for hypercalcemia of malignancy
• Adjustment of calcium and vitamin D supplementation in kidney disease
• Management of underlying endocrine disorders

When is emergency treatment necessary for hypercalcemia? Emergency intervention is typically required for severe hypercalcemia (calcium levels above 14 mg/dL) or when patients exhibit significant symptoms such as altered mental status, severe dehydration, or cardiac arrhythmias. Prompt medical attention is crucial in these cases to prevent life-threatening complications.

Long-Term Management and Monitoring of Hypercalcemia

Effective long-term management of hypercalcemia involves ongoing monitoring and adjustments to treatment plans. Key aspects of long-term care include:

1. Regular blood calcium level checks
2. Monitoring of related parameters (e.g., PTH, vitamin D, kidney function)
3. Bone density scans to assess skeletal health
4. Evaluation of potential complications (e.g., kidney stones, osteoporosis)
5. Adjustment of medications and supplements as needed
6. Patient education on dietary and lifestyle factors affecting calcium levels

How frequently should calcium levels be monitored in patients with a history of hypercalcemia? The frequency of monitoring depends on the underlying cause and the stability of calcium levels. Initially, more frequent checks (e.g., every 3-6 months) may be necessary. As the condition stabilizes, the interval between tests may be extended, but ongoing vigilance is essential.

Potential Complications of Chronic Hypercalcemia

Untreated or poorly managed hypercalcemia can lead to various complications:

• Kidney stones and nephrocalcinosis
• Osteoporosis and increased fracture risk
• Cardiovascular issues (e.g., hypertension, arrhythmias)
• Gastrointestinal problems (e.g., constipation, peptic ulcers)
• Neuropsychiatric symptoms (e.g., depression, cognitive impairment)

Recognizing and addressing these potential complications is crucial for maintaining overall health and quality of life in individuals with chronic hypercalcemia.

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).