Calcium Test
A blood test that measures calcium, important for bones, nerves, muscles and the heart.
Quick Summary
To check for high or low calcium, bone, kidney or parathyroid problems.
Total calcium (and sometimes ionised calcium).
No special preparation.
Overview
Calcium is controlled by vitamin D and parathyroid hormone.
Results are often corrected for albumin levels.
What It Measures
Total calcium
Blood level.
Ionised calcium
Active form, sometimes measured.
How It's Performed
- 01
Preparation
Usually no special preparation. Tell the staff about medicines you take.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm with a thin needle.
- 03
Afterwards
Press on the spot for a minute. A small bruise is common; you can go back to normal activities.
Reference Ranges
Note: Normal ranges vary by laboratory. Consult your report for the specific reference used.
| Parameter | Typical Range (Adult) | Units |
|---|---|---|
| Total calcium | 8.5–10.2 | mg/dL |
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories, ages and sexes; always use the range printed on your report and ask your doctor what your results mean.
If values are Low:
Low calcium can cause cramps and tingling; causes include vitamin D deficiency.
If values are High:
High calcium can cause thirst, tiredness and kidney stones; causes include overactive parathyroid.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Calcium Blood Test(opens in a new tab) · MedlinePlus, US National Library of Medicine