Patient education: Hypocalcemia (The Basics)

What is hypocalcemia? — This means having too little calcium in the blood.

Calcium is a mineral found in many foods and drinks. These include milk and other dairy products, green vegetables, and certain grains. Calcium helps keep bones and teeth strong. It is also important for the muscles, nerves, and heart to work normally.

Not having enough calcium in the blood can cause problems.

What causes hypocalcemia? — There are several possible causes. They include:

●Hypoparathyroidism – This is a disorder of the parathyroid glands. These are found near the thyroid, which is a butterfly-shaped gland in the middle of the neck (figure 1). These glands make a hormone called "parathyroid hormone," or "PTH." PTH helps control the amount of calcium in the blood. In people with hypoparathyroidism, their parathyroid glands do not make enough PTH. This can happen after surgery on the thyroid or other parts of the neck. It can also be caused by certain medical conditions.

●Not getting enough vitamin D from your diet – Your body needs vitamin D to absorb calcium from the foods you eat. Some medical conditions can also make it harder for your body to absorb calcium or vitamin D.

●Certain medicines

Other health problems can also cause low calcium levels.

What are the symptoms of hypocalcemia? — If your calcium level is only a little bit low, you might not notice any symptoms, especially if the level has decreased gradually. But if your level is very low, or if it drops suddenly, it can cause symptoms.

Symptoms can include:

●Numbness in the hands and feet or around the mouth

●Muscle cramps or spasms

●Mood changes

●Seizures

Is there a test for hypocalcemia? — Yes. Your doctor or nurse can do a blood test to measure the level of calcium in your blood. Sometimes, people learn that they have hypocalcemia after a routine blood test.

Your doctor or nurse might do other blood or urine tests, too. This can help them figure out what is causing your calcium level to be low.

How is hypocalcemia treated? — Treatment involves:

●Correcting your calcium level, if needed – If your calcium level is very low or if you have severe symptoms, you will need treatment in the hospital. This involves getting calcium by IV. (An IV is a thin tube that goes into a vein.) If your symptoms are mild and your calcium level is only a little bit low, you might get calcium supplements instead.

●Taking any other vitamins or minerals your body needs – Some people need extra vitamin D or magnesium.

●Treating the problem that caused your hypocalcemia – Treatment will depend on the health problem you have. For example, people with hypoparathyroidism usually need to take extra calcium and vitamin D for the rest of their life. They might need other treatments, too.

Can hypocalcemia be prevented? — If your hypocalcemia was caused by a specific health problem, getting treatment for that problem can prevent your calcium level from getting too low again.

It's also important to get enough calcium and vitamin D in your diet (figure 2). This cannot always prevent hypocalcemia. But it is important for your health.

When should I call the doctor? — Call your doctor or nurse for advice if you have any of the above symptoms of hypocalcemia again.

More on this topic

Patient education: Hypoparathyroidism (The Basics)
Patient education: Vitamin D deficiency (The Basics)
Patient education: Calcium and vitamin D for bone health (The Basics)
Patient education: Calcium blood test (The Basics)

Patient education: Vitamin D deficiency (Beyond the Basics)
Patient education: Calcium and vitamin D for bone health (Beyond the Basics)