What is hypocalcemia?
Hypocalcemia is a treatable condition that happens when the levels of calcium in your blood are too low.
Many different health conditions can cause hypocalcemia, and it’s often caused by abnormal levels of parathyroid hormone (PTH) or vitamin D in your body. Hypocalcemia can be mild or severe and temporary or chronic (lifelong).
What is calcium and what does it do?
Calcium is one of the most important and common minerals in your body. Most of your body’s calcium is stored in your bones, but calcium is needed in your blood as well.
The calcium in your blood helps your nerves work, helps make your muscles squeeze together so you can move, helps your blood clot if you are bleeding and helps your heart work properly. A low level of calcium in your blood (hypocalcemia) can hinder your body’s ability to perform these important functions. You also need calcium in your bones to make them strong.
If you don’t consume enough calcium in your diet, your body takes calcium from your bones to use in your blood, which can weaken your bones. Hypocalcemia happens when there are low levels of calcium in your blood, not your bones.
The levels of calcium in your blood and bones are controlled by two hormones called parathyroid hormone and calcitonin. Vitamin D also plays an important role in maintaining calcium levels because it’s needed for your body to absorb calcium.
Who gets hypocalcemia?
Hypocalcemia can affect people of all ages, including infants. The age at which someone could develop hypocalcemia usually depends on the cause. For example, if an infant has hypocalcemia, it’s often because of a genetic disorder.
How common is hypocalcemia?
Healthcare professionals and researchers have not yet determined how common hypocalcemia is. This is likely because hypocalcemia is usually a side effect of other health issues.
Hypocalcemia is a common side effect of having your thyroid removed (thyroidectomy). Approximately 7% to 49% of people have temporary hypocalcemia after thyroidectomy.
Symptoms and Causes
What are the symptoms of hypocalcemia?
People who have mild hypocalcemia often have no symptoms (are asymptomatic). The symptoms of hypocalcemia depend on if it’s mild or severe.
Symptoms of mild hypocalcemia can include:
- Muscle cramps, especially in your back and legs.
- Dry, scaly skin.
- Brittle nails.
- More coarse hair than what’s normal for you.
If left untreated, over time hypocalcemia can cause neurologic (affecting the nervous system) or psychologic (affecting the mind) symptoms, including:
Severe hypocalcemia (very low levels of calcium in your blood) can cause the following symptoms:
- Tingling in your lips, tongue, fingers and/or feet.
- Muscle aches.
- Muscle spasms in your throat that make it difficult to breathe (laryngospasm).
- Stiffening and spasms of your muscles (tetany).
- Abnormal heart rhythms (arrhythmia).
- Congestive heart failure.
What causes hypocalcemia?
There are many complex functions and factors involved with maintaining a steady level of calcium in your blood and body. Because of this, several different health conditions and disorders can cause hypocalcemia.
Most of the time, an issue with your parathyroid hormone (PTH) levels and/or vitamin D level(s) is involved with the cause of hypocalcemia. This is because PTH helps control the level of calcium in your blood and vitamin D helps your body absorb calcium.
The three most common causes of hypocalcemia include:
- Hypoparathyroidism: Hypoparathyroidism happens when your parathyroid glands (four small pea-sized glands behind your thyroid in your neck) don’t make enough parathyroid hormone (PTH). Low levels of PTH cause low levels of calcium in your body. You can have hypoparathyroidism from an inherited disorder or from having one or more of your parathyroid glands or your thyroid gland surgically removed.
- Vitamin D deficiency: Vitamin D helps your body absorb calcium properly, so a lack of vitamin D in the body can cause low levels of calcium in your blood (hypocalcemia). Vitamin D deficiency can be caused by an inherited disorder or by not getting enough sunlight or not consuming enough vitamin D.
- Kidney failure (renal failure): Hypocalcemia in chronic renal failure is due to an increased level of phosphorus in your blood and decreased renal production of a certain kind of vitamin D.
Other causes of hypocalcemia include:
- Certain medications: Bisphosphonates, corticosteroids, rifampin, calcitonin, chloroquine, cinacalcet, Denosumab, Foscarnet and plicamycin can all cause hypocalcemia.
- Pseudohypoparathyroidism: This is an inherited disorder that causes your body to not respond properly to the normal amount of parathyroid hormone (PTH) it has. Your body acts like it doesn’t have enough PTH when it actually has normal levels of PTH.
- Hypomagnesemia: Your parathyroid glands need magnesium to make and release parathyroid hormone (PTH), so when your magnesium is too low (hypomagnesemia), not enough PTH is produced and blood calcium levels are also lower (hypocalcemia).
- Pancreatitis: Approximately 15% to 88% of people who have acute pancreatitis will have hypocalcemia.
- Certain rare genetic disorders: Genetic mutations, such as DiGeorge syndrome, can cause hypocalcemia.
Diagnosis and Tests
How is hypocalcemia diagnosed?
You have hypocalcemia if your total serum (blood) calcium concentration is less than 8.8 mg/dL. Your healthcare provider may find mild hypocalcemia incidentally (by chance) from routine blood tests or by testing for other conditions.
What tests will be done to diagnose the cause of hypocalcemia?
Healthcare providers use a calcium concentration blood test to diagnose hypocalcemia. Figuring out and diagnosing the cause of hypocalcemia is just as important as diagnosing the hypocalcemia itself.
Your healthcare provider may perform the following tests or procedures to try to determine the cause of your hypocalcemia or to be sure your hypocalcemia isn’t affecting other parts of your body:
- Other blood tests: Your healthcare provider may do more blood tests to check your levels of magnesium, phosphorus, parathyroid hormone (PTH) and/or vitamin D.
- EKG (electrocardiogram): An EKG is a procedure that uses electrodes attached to your chest to measure your heart rhythm. Hypocalcemia can cause an abnormal heart rhythm.
- Bone imaging tests: Bone imaging tests could be used to see if you have calcium issues in your bones, such as osteomalacia or rickets.
Management and Treatment
How is hypocalcemia treated?
Oral calcium supplements are the most common treatment for hypocalcemia. Treating the cause of hypocalcemia is just as important as treating the hypocalcemia itself. If you’re taking a medication that is causing your hypocalcemia, your healthcare provider may change it or adjust it in order to return your calcium levels to normal.
What medications and treatments are used for hypocalcemia?
The following treatments and medications are often used for hypocalcemia:
- Oral calcium pills: Calcium pills or supplements may be used to restore your calcium to normal levels.
- Vitamin D supplement: People who have chronic hypocalcemia often take a vitamin D supplement along with calcium pills so that their bodies can properly absorb the calcium.
- Synthetic form of parathyroid hormone (PTH): If you have hypoparathyroidism that is causing hypocalcemia, your healthcare provider may have you take a synthetic form of PTH.
- IV calcium gluconate: If your hypocalcemia is severe and you are experiencing muscle cramps or spasms (tetany), you may receive an IV of calcium gluconate in the hospital.
- Other medications: Depending on the cause of your hypocalcemia, you may have to take other medications to treat/and or manage the cause.
What are the risk factors for hypocalcemia?
Risk factors for developing hypocalcemia can include having:
- Vitamin D deficiency.
- A parathyroid disorder or parathyroid gland surgery.
- Thyroid removal surgery (thyroidectomy).
- A family history of genetic conditions such as certain genetic mutations, genetic vitamin D disorder or DiGeorge syndrome.
Can I prevent hypocalcemia?
Unfortunately, there’s nothing you can do to prevent hypocalcemia. Although it may seem that eating and drinking more calcium could prevent hypocalcemia, a lack of calcium in your diet usually doesn’t affect the amount of calcium in your blood. Maintaining adequate calcium intake, however, is important for bone health.
Outlook / Prognosis
What is the prognosis (outlook) for hypocalcemia?
Hypocalcemia is a treatable condition. Symptoms of hypocalcemia usually go away once your calcium levels are back to normal. If left untreated, severe hypocalcemia can cause life-threatening complications such as seizures and congestive heart failure. Be sure to contact your healthcare provider if you’re experiencing symptoms and go to the nearest hospital if you are experiencing severe symptoms.
How long will I have hypocalcemia?
Depending on the cause, you could have temporary or chronic (lifelong) hypocalcemia. Ask your healthcare provider how long you can expect to have hypocalcemia and how long you’ll have to take medication.
Can I die from hypocalcemia?
Hypocalcemia can be potentially life-threatening if it’s not diagnosed and treated in time. Be sure to contact your healthcare provider if you’re experiencing symptoms.
When should I see my healthcare provider?
Be sure to contact your healthcare provider if you’re experiencing symptoms of hypocalcemia. If you have chronic hypocalcemia, it’s important to see your healthcare provider regularly so that you can be sure your calcium levels are healthy and that your treatment is working.
What questions should I ask my doctor if I have hypocalcemia?
If you’ve been diagnosed with hypocalcemia, it may be helpful to ask your healthcare provider the following questions:
- What caused my hypocalcemia?
- How long will I have hypocalcemia?
- How long will I have to take medication for my hypocalcemia?
- When will my symptoms go away once I start my medication for hypocalcemia?
- Are my children or family members at risk of developing hypocalcemia?
A note from Cleveland Clinic
Getting a diagnosis can be scary. Know that hypocalcemia is treatable and that symptoms usually go away once your calcium levels are back to normal with treatment. Don’t be afraid to ask your healthcare team questions about your hypocalcemia and its management.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy