Phosphorus Blood Test

What Is Phosphorus?

Phosphorus is a mineral that helps bones and teeth form. It also plays a role in making protein and energy, and keeping muscles and nerves working well.

What Is a Phosphorus Blood Test and Why Is It Done?

A phosphorus (FOSS-fer-iss) test measures the amount of phosphorus in the blood. Doctors may order a phosphorus test if a child has a medical condition that makes high or low phosphorus levels more likely, like a kidney problem.

Top Things to Know

• The phosphorus test checks the level of phosphorus (a mineral) in the blood.
• Doctors may order it if a child has a condition that could cause changes in phosphorus levels.
• Kids might need to stop taking certain medicines or not eat or drink before the blood test.
• Your doctor can explain what it means if phosphorus levels are too low or too high.

How Can I Help My Child Prepare for a Blood Test?

To help kids get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is nervous about it, work together on ways to stay calm. Deep breathing or even imagining being in a place that makes your child feel safe and relaxed can help.

What Do Phosphorus Test Results Mean?

Your doctor will explain what the results of the phosphorus test mean for your child. “Normal” phosphorus levels vary based on things like age and gender.

High phosphorus levels don’t always mean something’s wrong. Because kids’ bones are still growing, they tend to have more phosphorus in their bodies. But a high level could mean there’s a problem with the kidneys or parathyroid glands. Some medicines have phosphorus, and taking them for too long can raise the level as well.

A problem with the parathyroid glands and taking certain medicines may also cause low phosphorus levels. A low level might also happen when kids don’t get enough vitamin D (like with a condition called rickets) or phosphorus in food.

What Else Should I Know?

If phosphorus levels are high or low, your child may need other tests. If a low level is due to too little phosphorus in your child’s diet, your doctor can suggest foods that are high in phosphorus.

A phosphorus test may also be called a phosphate test. This is because phosphate (a kind of chemical) has phosphorus is in it.

If you have questions about the phosphorus test or what the results mean, talk to your doctor.