Calcium, Total (Serum)
This test measures the amount of calcium present 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.
["Understanding your total calcium levels helps identify potential imbalances that may affect your health."]
Key facts at a glance
- LOINC
- 10468-7
- Short code
- CALCAG
- Synonyms
- Calcit Ag Tiss Ql ImStn
- Category
- chemistry
- Sample
- serum
- Container
- 10% neutral buffered formalin container for paraffin-embedded tissue block or unstained tissue sections on positively charged glass slides
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- immune-stain
- CPT
- 88342
- SNOMED
- 39579002
- Specimen volume
- Tissue block or 4-5 micron thick sections on charged slides; minimum 1 representative tissue section
- Stability
- Formalin-fixed paraffin-embedded (FFPE) tissue blocks: stable indefinitely at room temperature. Unstained slides: stable for 1 year at room temperature. Fresh tissue: should be fixed within 24 hours of collection.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms like muscle weakness, bone pain, or unusual fatigue. It may also be done to check for conditions such as hyperparathyroidism, kidney disease, or metabolic bone diseases. Additionally, it could be part of a routine check-up or monitoring for certain medications or treatments.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted into a vein in your arm to draw a blood sample. This process is quick and usually painless. If you are on certain medications that can affect calcium levels, your provider will let you know if you need to adjust your timing.
What the Results Mean
Results are typically reported in milligrams per deciliter (mg/dL). While specific reference ranges can vary by lab, lower or higher than expected levels may indicate underlying health issues that need further evaluation.
Common Conditions Affecting Calcium Levels
Abnormal calcium levels can be linked to conditions like hypocalcemia (low calcium) which might cause numbness, spasms, or irregular heartbeat, or hypercalcemia (high calcium) which could lead to fatigue, nausea, or kidney stones. Proper diagnosis and treatment often involve addressing the underlying cause.
Reference range
Positive or Negative staining for calcitonin antigen in tissue. Results interpreted by pathologist based on staining intensity and distribution patterns. Reported as percentage of cells stained and staining intensity (0, 1+, 2+, 3+).N/A
No fasting required. Tissue specimen collection procedure should follow standard surgical or biopsy protocols. Patient consent for tissue analysis is required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Calcium is vital for numerous bodily functions, including maintaining bone density, muscle and nerve function, and blood clotting. Abnormal levels can signal underlying health issues such as thyroid disorders, kidney problems, or metabolic conditions. Regular monitoring is crucial for patients with chronic conditions that affect calcium metabolism.
Short name
Total Serum Calcium
Frequently asked questions
What causes low calcium levels?
What causes high calcium levels?
How often should I get 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