Foamy urine that does not go away for a long time indicates excessive urine protein, most commonly due to kidney disease, diabetes, etc. Long-term elevated urine protein elevates kidney function damage. Under normal circumstances, human urine does not contain protein or contains only trace amounts of protein, but when the kidneys are diseased, the protein flowing through the kidneys with the blood circulation will “leak” because of the reduced filtration function of the kidneys. Normal urine contains a lot of metabolic waste and the surface tension of the urine changes, so foam usually appears, but the foam is usually small and will dissipate after a few minutes of resting, which is normal. If there is an obvious increase in urine foam, similar to laundry detergent or beer foam, and does not disappear for a long time, it is considered to be caused by increased urine protein, which is commonly caused by kidney damage, such as acute and chronic nephritis, and can affect kidney function, creatinine, urea nitrogen and other indicators. If the foam in urine does not disappear for a long time, it is recommended that patients should visit the nephrology department of the hospital in time to check the urinary routine, 24h urine protein quantification, urological ultrasound and blood sugar and other indicators to clarify the cause of urine protein and treat the symptoms in order to improve and reduce proteinuria and reduce the foam in urine.