Phosphorus is important for bones, teeth, muscles and nerves as well as for maintaining the acid-base balance in the body. Our bones contain a large amount of phosphorus found in the body. The remaining is present in ATPs, nucleic acids and phospholipids and is also involved in carbohydrate metabolism. In the blood, phosphorus is found both in organically-bound phosphoric acid form and in inorganic phosphate form. Both low and high levels of phosphorus are associated with health issues. Therefore, inorganic phosphate is routinely measured in serum by biochemical assays.
Why is the test performed?
The phosphorus test is used to measure the levels of phosphorus in the blood, useful in the diagnosis and management of different types of disorders that are known to cause abnormal phosphorus levels.
When is the test ordered?
Phosphorus testing is ordered as a follow-up test to an abnormal calcium test and also when some of the following symptoms are visible:
- Muscle cramping
- Some bone related symptoms
The test may also be recommended when a patient shows signs and symptoms of an acid-base imbalance.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
It is better to inform the doctor about any medicine that the patient is on. This is because some medicines like laxatives, antacids and diuretics may affect the test results. Overnight fasting may be needed before collecting the sample.