Serum Calcium (Total)

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like muscle cramps, weakness, bone pain, or frequent fractures. It could also be part of a routine check-up, evaluation of kidney function, or monitoring for conditions like osteoporosis, hyperparathyroidism, or certain metabolic disorders.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a metabolic panel, but this isn’t always required for a standalone calcium test. Bring any medications you’re taking, as some can affect results.

What Happens During the Test

A healthcare professional will draw blood from a vein, typically in your arm. The process is quick and usually painless. You may feel a slight pinch or sting, but most people tolerate it well. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are compared to standard reference ranges, but exact values can vary by lab. Low calcium levels (hypocalcemia) may indicate conditions like vitamin D deficiency, kidney problems, or certain medications. High levels (hypercalcemia) could signal overactive thyroid, cancer, or other metabolic issues. Your provider will discuss findings in the context of your overall health.