Hyperphosphatemia describes an excess amount of phosphates in the blood - anything above the normal range of 1.45 mmol/L. This also tends to lower calcium levels (Hypocalcemia). It usually manifests with the growth of calcium crystals in soft tissues, hyperparathyroidism, and issues with both bone formation and kidney function.

It can be caused by many conditions, including hyperparathyroidism and kidney failure, which usually starts a positive feedback loop making either condition worse. It is also common in trauma cases as the breakdown of body tissues releases phosphate ions. In very rare cases, it can be caused by ingestion of large quantities of phosphates.

No matter what the cause, the condition can be managed with phosphate binders and avoiding foods with a high phosphate content.

Hyperphosphatemia at Wikipedia