Phosphate in Blood Test
A phosphate in blood test measures the amount of phosphate in your blood. Phosphate contains phosphorus, an electrolyte that helps build strong bones, make energy, and support nerve and muscle function. Abnormal levels can signal kidney disease, bone disorders, or parathyroid problems.
What this test measures
This test measures the amount of phosphate (a form of phosphorus) in a sample of your blood. Phosphate is an electrolyte that helps control fluid balance, acid-base balance, and is essential for bone health, energy production, and nerve and muscle function.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
A higher than normal phosphate level (hyperphosphatemia) may be linked to late stages of chronic kidney disease, kidney failure, hypoparathyroidism, acidosis, or long-term use of certain medicines like steroids, laxatives, or phosphate-containing enemas.
Lower-than-normal results
A lower than normal phosphate level (hypophosphatemia) may be caused by hyperparathyroidism, vitamin D deficiency, getting too little phosphorus from food, or long-term use of certain medicines like antacids containing aluminum hydroxide or calcium carbonate and certain diuretics.
Frequently asked questions
What is a phosphate in blood test?
It measures the amount of phosphate in your blood. Phosphate contains phosphorus, an electrolyte important for bone health, energy, and nerve function.
Why is this test done?
It helps diagnose or monitor kidney disease, bone disorders, and parathyroid disorders. It may also be used for people with poorly controlled diabetes or acid-base imbalances.
What do high phosphate levels mean?
High levels (hyperphosphatemia) can be a sign of chronic kidney disease, kidney failure, hypoparathyroidism, acidosis, or long-term use of certain medicines.
What do low phosphate levels mean?
Low levels (hypophosphatemia) can be caused by hyperparathyroidism, vitamin D deficiency, poor nutrition, or long-term use of certain medicines like antacids or diuretics.
Do abnormal levels always mean a medical condition?
No. Children often have higher levels due to growing bones. Also, mildly low levels may not be a health problem. Talk to your provider about your results.
Related lab tests
Sources
- MedlinePlus: Phosphate in Blood — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.