Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Hypocalcemia refers to low levels of calcium found on a blood test. It can cause symptoms like tingling, muscle cramps, and heart rhythm problems that can range from mild to life-threatening. Hypocalcemia is a particular problem for people who are hospitalized. One study found that over 20% of such people could be characterized as having hypocalcemia in addition to their other medical problems.
This article will take you through the symptoms and causes of hypocalcemia. It also addresses the diagnosis and treatment options available when your blood calcium levels fall too low.
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What Happens When Calcium Levels Are Low?
If your calcium is only a little low, you might not notice any symptoms from hypocalcemia. You are also less likely to experience symptoms if your calcium has been gradually lowering over time.
The signs of hypocalcemia include the following:
However, not everyone will experience all these symptoms. Sometimes symptoms are relatively mild, but in other cases, they may cause life-threatening problems. In someone who is already critically ill, having hypocalcemia may increase a person’s risk of death.
Causes of Hypocalcemia
Understanding Calcium Regulation
While calcium is a component of your bones, it is also found in your blood and inside your body’s cells. Calcium is involved in many important biological processes. For example, it plays roles in blood clotting and in helping certain enzymes to function. It is also critical for proper signaling in your nerves and muscles, including your heart muscle.
Because of this, your body works to tightly regulate the amount of calcium present in your blood. If it’s too high, it tries to bring it down; if it’s too low, it tries to raise it.
For example, if your calcium levels are too low, your parathyroid glands will normally releaseparathyroid hormone(PTH). This hormone works to increase your calcium in different ways, like reducing the amount of calcium released in your urine. Normally, the action of PTH brings the calcium back into a normal range. But hypocalcemia can result if something lowers your blood calcium but your body can’t respond normally to increase calcium levels.
Underlying Causes Leading to Hypocalcemia
Hypocalcemia can have many different potential underlying causes. Because of the key role of PTH, it is not surprising that a low level of this hormone (calledhypoparathyroidism) is one of the main causes of low calcium. Some of the reasons for this include injury to the parathyroid gland from surgery or radiation treatment, autoimmune disease, or a genetic disease leading to low PTH.
Low vitamin D is also another important cause of hypocalcemia. This hormone plays an important role in your body’s ability to absorb and utilize calcium. People can have low vitamin D from several different problems, such as:
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Problems with certainblood electrolytescan also sometimes lead to hypocalcemia. For example, abnormal levels of the electrolytes magnesium and phosphate might indirectly cause hypocalcemia. Some other less common causes of hypocalcemia includepancreatitisand cancer which has spread to the bones.
Medications sometimes cause hypocalcemia as a side effect. Some of these include the following:
For a variety of reasons, people who are critically ill have a higher risk of hypocalcemia. This can be due to underlying medical problems, sepsis, electrolyte problems, certain kinds of blood transfusions that affect calcium, or other factors.
Diagnosis of Hypocalcemia
Various signs and symptoms might make a clinician suspect hypocalcemia. Your healthcare provider will take a full medical history and ask you about your recent symptoms. Things like muscle cramps or pain and tingling in the fingers might make the clinician think of hypocalcemia.
A complete exam is also an important part of diagnosis. Your healthcare provider might tap you lightly at a certain place on your cheek. People with hypocalcemia may involuntarily contract their facial muscles in response.
Blood Tests
A definitive diagnosis of hypocalcemia requires ablood test for calcium. Calcium is a common blood test often performed with other tests as part of a basic metabolic panel (BMP) or a complete metabolic panel (CMP).
Calcium is usually first assessed through a total calcium blood test. This measures the calcium that is free in the blood as well as the calcium that is bound to a common protein in the blood (called albumin).
If this test is low, you might need a test of youralbumin. This can help your clinician get a more accurate idea about whether your calcium level is a problem. Sometimes, if your albumin is low, it might mean that you don’t have hypocalcemia, even if this was indicated on a previous test.
Hypocalcemia is usually defined as having a corrected total serum calcium of less than 2.12 mmol/L.“Corrected” refers to a certain way of measuring calcium that accounts for albumin.
However, recognizing that hypocalcemia is present is only the first step. It is also critical to find the underlying reason that the person has low levels of calcium in their blood. This often requires additional testing.
Additional blood tests might include the following:
Depending on the context, you might also need other tests, such as urine tests for calcium, phosphate, or other electrolytes. Some people might need additional monitoring tests, like anEKGto check that their heart rhythm is OK.
Hypocalcemia Treatment
Treatment for hypocalcemia will vary based on several factors. These include the underlying cause and the severity of the problem.
If a person’s calcium suddenly drops very low, they will likely need to receive calcium through an intravenous (IV) line right away. This can raise a person’s calcium level more quickly than oral calcium supplements. People receiving IV calcium need to be carefully monitored in a hospital setting.
People who have calcium that is not as low can usually takeoral calcium supplementsinstead. You may need to take these over a long period. Vitamin D is also often a key component of treatment.
Depending on the situation, you might need to take other substances important for calcium metabolism, like magnesium. Or you might need to stop taking a medication that lowers your calcium too much. In some situations, you may need to take a new medication (like certain types of diuretics) that may be able to help you increase your calcium.
Other treatments may be necessary, depending on the circumstances. For example, you might need treatment for an underlying condition, like kidney or liver disease. Some people with hypoparathyroidism take a PTH replacement hormone that may help increase calcium to normal levels.
You are likely to need follow-up monitoring if you are found to have hypocalcemia. This is to check that your calcium has returned to normal and your treatment hasn’t increased it too much. This can cause elevated calcium (hypercalcemia) which causes different medical problems. Your healthcare provider will help tailor your treatment and monitoring schedule to your specific circumstance.
Summary
Hypocalcemia is low levels of calcium in the blood. Symptoms include muscle cramps, numbness and tingling in fingertips, toes, and around the mouth, and more serious issues like heart rhythm problems that can range from mild to life-threatening. Hypocalcemia can be especially problematic for those who are already sick. Fortunately, low calcium levels can usually be corrected intravenously or through supplementation.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Catalano A, Chilà D, Bellone F, et al.Incidence of hypocalcemia and hypercalcemia in hospitalized patients: Is it changing?J Clin Transl Endocrinol. 2018;13:9–13. doi:10.1016/j.jcte.2018.05.004Schafer AL, Shoback DM.Hypocalcemia: Diagnosis and Treatment. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.Miura S, Yoshihisa A, Takiguchi M, et al.Association of hypocalcemia with mortality in hospitalized patients with heart failure and chronic kidney disease.J Card Fail. 2015;21(8):621-7. doi:10.1016/j.cardfail.2015.04.015Children’s Hospital of Philadelphia.Hypocalcemia.Do WS, Park JK, Park MI, et al.Bisphosphonate-induced severe hypocalcemia—A case report.J Bone Metab. 2012;19(2):139–145. doi:10.11005/jbm.2012.19.2.139Oh SW, Han SY.Loop diuretics in clinical practice.Electrolyte Blood Press. 2015;13(1):17–21. doi:10.5049/EBP.2015.13.1.17Pepe J, Colangelo L, Biamonte F, et al.Diagnosis and management of hypocalcemia.Endocrine. 2020;69(3):485-495. doi:10.1007/s12020-020-02324-2Additional ReadingFong J, Khan A.Hypocalcemia: updates in diagnosis and management for primary care.Can Fam Physician.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Catalano A, Chilà D, Bellone F, et al.Incidence of hypocalcemia and hypercalcemia in hospitalized patients: Is it changing?J Clin Transl Endocrinol. 2018;13:9–13. doi:10.1016/j.jcte.2018.05.004Schafer AL, Shoback DM.Hypocalcemia: Diagnosis and Treatment. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.Miura S, Yoshihisa A, Takiguchi M, et al.Association of hypocalcemia with mortality in hospitalized patients with heart failure and chronic kidney disease.J Card Fail. 2015;21(8):621-7. doi:10.1016/j.cardfail.2015.04.015Children’s Hospital of Philadelphia.Hypocalcemia.Do WS, Park JK, Park MI, et al.Bisphosphonate-induced severe hypocalcemia—A case report.J Bone Metab. 2012;19(2):139–145. doi:10.11005/jbm.2012.19.2.139Oh SW, Han SY.Loop diuretics in clinical practice.Electrolyte Blood Press. 2015;13(1):17–21. doi:10.5049/EBP.2015.13.1.17Pepe J, Colangelo L, Biamonte F, et al.Diagnosis and management of hypocalcemia.Endocrine. 2020;69(3):485-495. doi:10.1007/s12020-020-02324-2Additional ReadingFong J, Khan A.Hypocalcemia: updates in diagnosis and management for primary care.Can Fam Physician.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Catalano A, Chilà D, Bellone F, et al.Incidence of hypocalcemia and hypercalcemia in hospitalized patients: Is it changing?J Clin Transl Endocrinol. 2018;13:9–13. doi:10.1016/j.jcte.2018.05.004Schafer AL, Shoback DM.Hypocalcemia: Diagnosis and Treatment. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.Miura S, Yoshihisa A, Takiguchi M, et al.Association of hypocalcemia with mortality in hospitalized patients with heart failure and chronic kidney disease.J Card Fail. 2015;21(8):621-7. doi:10.1016/j.cardfail.2015.04.015Children’s Hospital of Philadelphia.Hypocalcemia.Do WS, Park JK, Park MI, et al.Bisphosphonate-induced severe hypocalcemia—A case report.J Bone Metab. 2012;19(2):139–145. doi:10.11005/jbm.2012.19.2.139Oh SW, Han SY.Loop diuretics in clinical practice.Electrolyte Blood Press. 2015;13(1):17–21. doi:10.5049/EBP.2015.13.1.17Pepe J, Colangelo L, Biamonte F, et al.Diagnosis and management of hypocalcemia.Endocrine. 2020;69(3):485-495. doi:10.1007/s12020-020-02324-2
Catalano A, Chilà D, Bellone F, et al.Incidence of hypocalcemia and hypercalcemia in hospitalized patients: Is it changing?J Clin Transl Endocrinol. 2018;13:9–13. doi:10.1016/j.jcte.2018.05.004
Schafer AL, Shoback DM.Hypocalcemia: Diagnosis and Treatment. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.
Miura S, Yoshihisa A, Takiguchi M, et al.Association of hypocalcemia with mortality in hospitalized patients with heart failure and chronic kidney disease.J Card Fail. 2015;21(8):621-7. doi:10.1016/j.cardfail.2015.04.015
Children’s Hospital of Philadelphia.Hypocalcemia.
Do WS, Park JK, Park MI, et al.Bisphosphonate-induced severe hypocalcemia—A case report.J Bone Metab. 2012;19(2):139–145. doi:10.11005/jbm.2012.19.2.139
Oh SW, Han SY.Loop diuretics in clinical practice.Electrolyte Blood Press. 2015;13(1):17–21. doi:10.5049/EBP.2015.13.1.17
Pepe J, Colangelo L, Biamonte F, et al.Diagnosis and management of hypocalcemia.Endocrine. 2020;69(3):485-495. doi:10.1007/s12020-020-02324-2
Fong J, Khan A.Hypocalcemia: updates in diagnosis and management for primary care.Can Fam Physician.
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