What is causing you to get this checked? Do you have an ongoing situation? Yes, your phosphorous level was too high at your last time it was checked. The normal range for phosphorous is 2.5-4.5 mg/dL. So, the other times it was within normal. If your kidneys aren't functioning properly, phosphorous 'can' build up. https://www.kidneyfund.org/kidney-disease/chronic-kidney-disease-ckd/complications/high-phosphorus/ You are only slightly elevated at this point. What does your doctor say? What are your other test results? Do you follow up to check again. Ways to lower phosphorous: Reduce the amount of phosphorus you eat. ...
Take phosphorus binders. ...
Take vitamin D. ...
Take a calcimimetic medicine. ...
Stay on dialysis the entire time. ...
Start an exercise program approved by a doctor. ...
Get an operation to remove some of the parathyroid glands.
Let me know what else the doctor has said. That your other indicators are normal is a good sign.