Blood test
Calcium Blood Test
A calcium blood test measures the level of calcium in your blood, which is important for bones, nerves and muscles. It helps find causes of high or low calcium.
Quick answer
Calcium Blood Test: what it is and what the results mean
Calcium is a mineral vital for bones, teeth, nerves and muscle function. A calcium blood test measures the level in the blood, often as part of a "bone profile" that also includes related measures.
- Why it is done: It is used to investigate symptoms such as tiredness, bone pain, kidney stones or muscle problems, to check parathyroid and bone health, and to monitor certain conditions and medicines.
- Understanding results: A high calcium can result from an overactive parathyroid gland or other causes and may need investigation, while a low calcium can cause muscle and nerve symptoms.
What it is
Calcium is a mineral vital for bones, teeth, nerves and muscle function. A calcium blood test measures the level in the blood, often as part of a "bone profile" that also includes related measures.
Why it is done
It is used to investigate symptoms such as tiredness, bone pain, kidney stones or muscle problems, to check parathyroid and bone health, and to monitor certain conditions and medicines.
What to expect
It is a standard blood test from the arm. Results are often interpreted alongside albumin (a protein that carries calcium) and sometimes parathyroid hormone and vitamin D.
Understanding the results
A high calcium can result from an overactive parathyroid gland or other causes and may need investigation, while a low calcium can cause muscle and nerve symptoms. Results are adjusted for albumin and read with related tests.
Good to know
Risks and limitations
The blood test is very safe. Calcium levels are affected by protein levels and other factors, so an "adjusted" calcium and further tests are used to interpret an abnormal result.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Calcium Blood Test: frequently asked questions
What does high calcium mean?
Raised calcium has several causes, commonly an overactive parathyroid gland. It can cause tiredness, thirst, kidney stones and other symptoms, and usually prompts further tests to find the cause.
What is a bone profile blood test?
A bone profile measures calcium along with related substances such as phosphate, albumin and an enzyme (ALP), giving a fuller picture of bone and mineral health.
Related tests
Other blood test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
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