Calcium (Ca) is an ion that is essential for many body processes, including nerve conduction, muscle contraction, and bone metabolism.
How the Test is Performed
Calcium level is performed on a small sample of blood (a few millilitres) from a vein or an artery.
Medical Conditions and Symptoms
Calcium and Phosphate are often requested together as part of a “metabolic bone profile”. These tests are usually normal in osteoporosis (“thinning of the bones”) but are helpful to exclude other metabolic bone conditions.
The symptoms of hypercalcaemia (high calcium level in the blood) can be quite non-specific and include the so-called “bones, groans and kidney stones”, namely bony pain (due to a process within the bones causing a high calcium level), and abdominal pain which may be diffuse (“groans”) or localsied to the kidney area as in kidney stones (renal colic, ureteric colic). Hypercalcaemia may also cause thirst, lethargy, and very rarely, an altered conscious state. Patients with some haematological cancers, or cancers which arise in bones or spread to bones, are more prone to this condition.
Low serum calcium (hypocalcaemia) is quite rare and is almost confined to people who have had their parathyroid glands removed or damaged by surgery. It causes painful muscle spasms, known as tetany (not to confused with tetanus, an infectious disease caused by the bacterium Clostridium tetani).
Test Results Explained
Because Calcium is transported in the blood mostly bound to the protein Albumin, a serum Calcium level needs to be taken in context of the Albumin level, and there are various formulas for calculating this “corrected Calcium”. In uncommon circumstances, an arterial blood sample may have to be taken to check the ionised Calcium level, which is the biochemically active fraction of calcium not bound to Albumin.
- General Practitioner (GP)
- Emergency Physician
- General Physician
- Renal Physician
Also Known As
- Serum Calcium