Triple Phosphate Crystals

Triple phosphate crystals, also known as magnesium ammonium phosphate crystals, are found in alkaline urine (pH greater than 7). The formation of magnesium ammonium phosphate crystals (triple phosphate crystals) is caused by a combination of factors including decreased urine volume combined with bacteria in the renal system that are capable of producing ammonia and increasing the urine pH (such as Proteus or Klebsiella-type bacteria).

In individuals with kidney stones, the repeated presence of triple phosphate crystals could predict the formation of a struvite (magnesium ammonium phosphate) stone. It should be noted, however, that most patients with triple phosphate crystals will never form stones.