Hypercalcemia means you have too much calcium in your blood. Most people don’t know they have it until a routine blood test reveals the problem. While calcium is essential for strong bones, muscle function, and nerve health, too much of it can interfere with how your body works. This article explains what hypercalcemia is, what causes it, how it is diagnosed, and how it is treated in Canada.
What Is Hypercalcemia?
Your body depends on calcium every day. It keeps your bones strong, helps your muscles contract, supports nerve signals, and helps release hormones properly.
However, when calcium levels in your blood rise too high, these same processes can be disrupted. This condition is called hypercalcemia. According to Mayo Clinic, hypercalcemia is most often caused by overactive parathyroid glands or certain types of cancer.
Mild cases may cause no noticeable symptoms at all. More severe cases, however, can seriously affect your kidneys, bones, and heart. Early detection through blood testing is the best way to catch hypercalcemia before complications develop.
Symptoms of Hypercalcemia
Many people with mild hypercalcemia have no obvious symptoms. In fact, the condition is often discovered accidentally during routine bloodwork. As a result, it is easy to overlook without regular health checkups.
When symptoms do appear, they tend to get worse as calcium levels rise higher. Furthermore, older adults may experience muscle pain and weakness even when calcium levels are only slightly elevated.
Common Symptoms to Watch For
Severe hypercalcemia can cause a wide range of symptoms. These include:
Nausea and vomiting
Loss of appetite
Feeling excessively thirsty
Frequent urination
Constipation
Abdominal pain
Muscle weakness
Joint pain
Confusion or difficulty thinking clearly
Unusual fatigue and sluggishness
Irregular heartbeat
It is important to note that the severity of symptoms does not always match the level of calcium in the blood. For example, some people with moderately high calcium feel very unwell, while others with similarly high levels feel completely fine.
Causes of Hypercalcemia
Several different conditions and factors can raise your blood calcium levels. Understanding the root cause is essential for choosing the right treatment. Here are the most common causes of hypercalcemia.
Overactive Parathyroid Glands
The most common cause of hypercalcemia is a condition called primary hyperparathyroidism. Your parathyroid glands sit behind your thyroid gland in your neck. When one or more of these glands become overactive, they release too much parathyroid hormone, which pulls calcium from your bones into your blood.
Cancer
Certain cancers significantly raise the risk of developing hypercalcemia. Lung cancer, breast cancer, and multiple myeloma (a blood cancer) are among the most common linked cancers.
Some cancerous tumours produce a protein that mimics parathyroid hormone. This triggers the release of calcium from bones into the bloodstream. In addition, when cancer spreads (metastasizes) to the bones, it can further elevate blood calcium levels. This is known as a paraneoplastic syndrome — the body’s response to the presence of cancer or substances produced by the tumour.
Other Medical Conditions
Some inflammatory diseases — such as tuberculosis, sarcoidosis, and other granulomatous diseases — can raise levels of vitamin D (calcitriol) in the body. Higher calcitriol levels cause your gut to absorb more calcium than normal, leading to hypercalcemia.
There is also a rare genetic condition called familial hypocalciuric hypercalcemia. In this disorder, calcium receptors in the body do not work properly, causing blood calcium to rise.
Prolonged Immobility
People who must stay in bed for long periods — due to illness, injury, or recovery from surgery — can develop hypercalcemia over time. When bones are not used or stressed through movement, they begin to release calcium into the bloodstream.
Medications and Supplements
Some medications can trigger hypercalcemia. For example, lithium — used to treat bipolar disorder — can stimulate the release of parathyroid hormone. Thiazide diuretics may also affect how much calcium your kidneys remove from the body.
Furthermore, taking large amounts of calcium or vitamin D supplements over time can push calcium levels above the normal range. Always speak with your pharmacist or family doctor before starting new supplements.
Dehydration
Dehydration is a frequent cause of mild or temporary hypercalcemia. When there is not enough fluid in your blood, the concentration of calcium rises. Drinking adequate fluids daily helps keep calcium levels stable. Health Canada provides guidance on recommended calcium and fluid intake for Canadians of all ages.
How Hypercalcemia Is Diagnosed
Because hypercalcemia often causes no symptoms, many Canadians discover the condition through routine blood tests ordered by their family doctor. A simple blood panel can measure calcium levels and detect whether they fall outside the normal range.
If your calcium is high, your doctor will also check your parathyroid hormone (PTH) levels. Elevated PTH points toward hyperparathyroidism as the likely cause.
Further Testing
If your parathyroid hormone levels are normal, your doctor may order additional tests to find the underlying cause of your hypercalcemia. These investigations can include:
Chest X-rays
CT (computed tomography) scans
MRI (magnetic resonance imaging)
Mammography
Other cancer screening tests
These tests help your medical team determine whether lung disease, breast cancer, granulomatous disease, or another condition is behind the elevated calcium. Your provincial health plan typically covers medically necessary diagnostic imaging when ordered by a physician.
Treatment Options for Hypercalcemia
Treatment for hypercalcemia depends on how severe the condition is and what is causing it. Mild cases may simply require monitoring and treating the underlying cause. Severe cases, however, need prompt medical attention.
Hospital Treatment for Severe Hypercalcemia
If your calcium levels are dangerously high, you may need to be admitted to hospital. Urgent treatment protects your kidneys and bones from damage. Hospital treatments can include:
Intravenous (IV) fluids — to rehydrate the body and dilute calcium in the blood
Loop diuretics (such as furosemide) — to help the kidneys flush out excess calcium
IV bisphosphonates (such as pamidronate or zoledronate) — to slow bone breakdown and reduce calcium release
Glucocorticoids — to counteract the effects of excess vitamin D
Dialysis (hemodialysis or peritoneal dialysis) — used in serious cases when the kidneys are damaged and other treatments have not worked
Long-Term Management
Once calcium levels stabilise, your doctor will focus on treating the root cause. For example, if overactive parathyroid glands are responsible, surgery to remove the affected gland may be recommended. If a medication is to blame, your doctor may adjust your prescription.
For mild, chronic hypercalcemia, regular monitoring through blood tests and staying well-hydrated are often the first steps. According to Healthline, lifestyle adjustments and careful management of supplements can also make a meaningful difference in mild cases.
Possible Complications of Hypercalcemia
Left untreated, hypercalcemia can lead to serious long-term health problems. It is important to address high calcium levels early to prevent these complications.
Possible complications include:
Osteoporosis — as bones lose calcium into the blood, they become weaker and more prone to fractures
Kidney stones — excess calcium in the urine can form painful stones in the kidneys
Kidney failure — severe, prolonged hypercalcemia can permanently damage the kidneys and reduce their ability to filter waste from the blood
Nervous system problems — very high calcium levels can cause confusion, memory issues, and in extreme cases, coma
Abnormal heart rhythms — high calcium can interfere with the electrical signals that control your heartbeat
When to See a Doctor
If you notice any of the symptoms listed above — especially unusual fatigue, muscle weakness, confusion, or frequent urination — it is a good idea to get checked out. These symptoms can point to many conditions, and only a blood test can confirm whether hypercalcemia is the cause.
You can start by booking an appointment with your family doctor. If you do not have a family doctor, a walk-in clinic can order basic blood tests and refer you to a specialist if needed. Many provincial health plans cover blood calcium testing when it is medically indicated.
Do not wait if your symptoms are severe. Chest pain, extreme confusion, or an irregular heartbeat are reasons to go to your nearest emergency department right away.
As always, please consult your doctor or a qualified healthcare provider before making any changes to your medications, supplements, or treatment plan. This article is for informational purposes only and does not replace professional medical advice.
Frequently Asked Questions About Hypercalcemia
What are the first signs of hypercalcemia?
The early signs of hypercalcemia are often subtle and easy to miss. Many people experience fatigue, mild nausea, increased thirst, or frequent urination before other symptoms appear. Because hypercalcemia can also cause no symptoms at all, routine blood tests are the most reliable way to catch it early.
What is the most common cause of hypercalcemia?
The most common cause of hypercalcemia is primary hyperparathyroidism — a condition where one or more of the parathyroid glands become overactive and release too much parathyroid hormone. Cancer is the second most common cause, particularly lung cancer, breast cancer, and multiple myeloma.
Can too many calcium supplements cause hypercalcemia?
Yes, taking very high doses of calcium or vitamin D supplements over a long period of time can raise your blood calcium above normal levels, leading to hypercalcemia. It is important to follow recommended dosage guidelines and speak with your family doctor or pharmacist before adding supplements to your routine.
Is hypercalcemia dangerous?
Mild hypercalcemia is usually manageable and may not cause serious harm. However, severe or untreated hypercalcemia can lead to kidney stones, kidney failure, weakened bones (osteoporosis), irregular heartbeat, and neurological problems. Early detection and treatment are key to preventing these complications.
How is hypercalcemia treated in Canada?
Treatment for hypercalcemia in Canada depends on its severity and underlying cause. Mild cases are often managed by treating the root condition and monitoring calcium levels regularly through bloodwork ordered by your family doctor. Severe cases may require hospitalisation for IV fluids, diuretics, or bisphosphonate medications, all of which are available through the Canadian healthcare system.
Can dehydration cause hypercalcemia?
Yes, dehydration is a common and often overlooked cause of mild or temporary hypercalcemia. When your body lacks sufficient fluids, the concentration of calcium in your blood rises. Staying well-hydrated is a simple but effective way to help prevent mild hypercalcemia from developing.
Key Takeaways
Hypercalcemia means your blood calcium level is higher than normal.
It often causes no symptoms, especially in mild cases, and is frequently found through routine blood tests.
The most common causes are overactive parathyroid glands and certain cancers.
Other causes include dehydration, long-term immobility, certain medications, and excessive supplement use.
Severe hypercalcemia can cause kidney damage, osteoporosis, and heart rhythm problems if left untreated.
Treatment ranges from monitoring and hydration for mild cases to hospitalisation and IV therapy for severe cases.
If you have concerns about your calcium levels, speak with your family doctor or visit a walk-in clinic to arrange a blood test.
