Serum Calcium (with Specimen Collection and Potential Clinical Context)
This test measures the amount of calcium in your blood serum. Calcium is an essential mineral that plays a key role in many bodily functions, including muscle contraction, nerve signaling, and bone health.
["Your blood calcium levels help ensure proper bone strength and normal heart and nerve function."]
Key facts at a glance
- LOINC
- 44179-0
- Short code
- XR Sacrum+Coccyx 2V
- Synonyms
- XR Sacrum+Coccyx 2V
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xr
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Doctors may order a serum calcium test to check for conditions like low or high calcium levels, which can affect bones, muscles, nerves, or heart function. It might also be done to monitor certain treatments or diagnose symptoms such as muscle spasms, bone pain, or abnormal heart rhythms.
What Does the Test Involve?
A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab for analysis. Calcium levels are measured in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).
What Are Common Causes of Abnormal Results?
Low calcium (hypocalcemia) can result from conditions like vitamin D deficiency, kidney problems, or certain medications. High calcium (hypercalcemia) may be linked to overactive thyroid, cancer, or prolonged bed rest.
What Do My Results Mean?
Results are interpreted by your healthcare provider based on your overall health, symptoms, and medical history. They may also compare your results to a baseline from previous tests. If results are outside the normal range, further testing or evaluation may be needed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Serum calcium levels are critical for maintaining normal physiological functions. Hypocalcemia can lead to muscle cramps, seizures, or irregular heartbeats, while hypercalcemia may cause fatigue, nausea, kidney stones, or confusion. Monitoring calcium levels helps in diagnosing and managing conditions affecting bone metabolism, endocrine disorders, or cancer-related bone disease.
Frequently asked questions
What does a serum calcium test measure exactly?
How long does it take to get the results of this test?
Can I eat or drink anything before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy