Calcium, Total (Serum)
This test measures the amount of calcium in your blood serum, which is important for maintaining healthy bones, muscle function, and nerve signaling.
["Your blood calcium levels help support bone health and vital bodily functions."]
Key facts at a glance
- LOINC
- 60656-6
- Short code
- CD-GO
- Synonyms
- Cd-Go Skull XR
- Category
- chemistry
- Sample
- serum
- Container
- N/A - Radiographic imaging procedure, not a specimen-based test
- Units
- N/A
- Ref low
- 95
- Ref high
- 130
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–99 years
- Method
- xr-measured
- CPT
- 70350
- SNOMED
- 39579001
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
Why Is This Test Done?
Doctors may order this test to check for conditions like low or high calcium levels, which can affect bones, muscles, or the heart. It may also be used to monitor certain medical treatments or diagnose symptoms such as muscle spasms, confusion, or abnormal heart rhythms.
What Does a Low or High Calcium Level Mean?
Low calcium levels (hypocalcemia) can cause muscle cramps, numbness, or an irregular heartbeat. High calcium levels (hypercalcemia) may lead to fatigue, nausea, or kidney problems. Your doctor will interpret results in relation to your overall health and symptoms.
How Is This Test Performed?
A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab for analysis. No special preparation is typically needed, but you may be asked to fast for 8–12 hours before the test if instructed by your doctor.
What Are Common Causes?
Calcium levels can be affected by conditions like osteoporosis, kidney disease, thyroid disorders, or certain medications. Dietary factors (such as calcium-rich foods or vitamin D levels) and hormonal imbalances can also influence results.
Reference range
Adult males: approximately 105-130 mm; Adult females: approximately 95-120 mm. Values vary based on population, ethnicity, and measurement technique. Reference ranges should be established by each institution based on their patient population.N/A
No special preparation required. Patient should remove all metallic objects, jewelry, dentures, and hair accessories from the head and neck region prior to imaging.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal calcium levels can indicate underlying health issues, such as metabolic bone diseases, endocrine disorders, or kidney dysfunction. Regular monitoring is crucial for patients with conditions like hyperparathyroidism or chronic kidney disease.
Short name
Total Serum Calcium
Frequently asked questions
What happens if my calcium levels are out of range?
Will I need to fast before this test?
How long will it take to get my results?
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