Calcium
Also known as: Ca, Serum calcium, Total calcium
Calcium is a mineral essential for your bones, muscles, nerves, and heart. The blood test measures the calcium circulating in your blood, which your body keeps within a narrow range.
Why it's measured
Calcium is part of routine metabolic panels. Because blood calcium is tightly regulated and partly bound to albumin, doctors sometimes interpret it together with your albumin level.
Typical range
Reference ranges vary by lab. Since a portion of calcium travels bound to albumin, your doctor may take your albumin into account when interpreting the number.
What high values can mean
A higher calcium is a value doctors look at in context, sometimes alongside albumin and other tests, and may confirm with repeat testing.
What low values can mean
A lower calcium is similarly interpreted alongside albumin and your broader picture rather than on its own.
Questions to ask your doctor
- Should my calcium be interpreted alongside my albumin?
- Does this need rechecking?
- Are there related tests we should look at?
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Try the explainerEducational information only — not medical advice, diagnosis, or treatment. Reference ranges vary by lab; always use your own lab's range and discuss results with a qualified clinician.