The presence of urate crystals, sometimes called “amorphous urate crystals,” is generally of little clinical significance. They are found in acidic urine (pH less than 5.5). The formation of amorphous urate crystals can be caused by a combination of factors, including a diet rich in meat, decreased urine volume or a condition that acidifies urine such as chronic diarrhea. They are also present in individuals who have gout or during chemotherapy.
In individuals who have kidney stones, the repeated presence of amorphous urate crystals in the urine may indicate the probable nature of the stones. It should be noted, however, that most patients with amorphous urate crystals will never form stones.