Possible causes of white precipitates in urine: 1. The presence of urinary tract infection. In this case, the urine can be mixed with bacterial metabolites or pus cells, which can be manifested as cloudy urine, white color, visible precipitates, accompanied by symptoms such as frequent urination, urinary urgency, painful urination or blood in the eyes. The presence of crystalline urine or salt urine can be identified by urine routine and urine culture tests. 2. The presence of crystals in the urine or the white color of the urine, and the presence of small precipitates when the urine is left to stand, may be related to the increase of salts or uric acid in the urine, and the oversaturation of the composition in the urine and the precipitation of crystals. Usually there are no symptoms of urinary tract irritation and a routine urinalysis or crystallography is required, as well as a blood uric acid level check, etc.