A phosphorus blood test or phosphate test is used to detect the amount of phosphate present in a blood sample. Phosphate is an ion or a charged particle containing phosphorus. Phosphorus is required by the body for the building and repairing of bones and teeth. Nerve functioning and muscle contractions are also regulated with the help of phosphorus. Around 85 per cent of the phosphorus in the body is present in the bones, while the rest is contained in tissues of the body.
The phosphate content in the blood is managed by the kidneys. The kidneys filter the excess phosphate from the blood, which is then eliminated from the body through the urine. High phosphate levels in the blood are usually indicative of a kidney problem. The phosphate level in the blood also has an effect on the calcium level in the blood. Both phosphate and calcium have opposite reactions. As the calcium level in the blood is elevated, the phosphate level falls. Certain infections and disease may cause a disruption in the relation between phosphate and calcium. As such both may be measured simultaneously. A phosphate blood test is ordered to measure the levels of phosphate in individuals with bone or kidney disease. Such a test may also be done to detect problems in glands such as the parathyroid glands.
There are several medications that can affect the test results. It is important to inform the doctor about all medications that are currently being taken.
The test involves obtaining a sample of blood by inserting a needle into the arm of the individual. Prior to this an elastic band may be wrapped around the individual’s upper arm to obstruct the blood flow. This will enlarge the veins and allow for easier insertion of the needle. The site where the needle will be inserted is then cleaned with alcohol and the needle is inserted into the vein. The blood is collected in a tube attached to the needle and once sufficient blood has been collected, the band is removed. A cotton ball or a piece of gauze is placed over the site and pressure is applied to the area before putting on a small bandage.
High phosphate levels may result from kidney disease, parathyroid underactivity, bone diseases, excess of vitamin D, reduction in magnesium levels and also pregnancy. Low phosphate levels are indicative of hyperthyroidism, bone disease, vitamin D deficiency, liver or kidney disease, excessive alcohol consumption and high calcium content.