Urine with foam for a long time does not disappear may be a normal phenomenon, but also may be nephrotic syndrome, urinary tract infection, diabetes caused. 1. Normal phenomenon: for example, holding too much urine, urinating with a greater impact, urinating faster, so that the surface tension increases, a large number of bubbles can appear. This situation is no need to treat. 2. Nephrotic syndrome: patients with nephrotic syndrome can have urine foam for a long time without disappearing, in addition to the symptoms of large amounts of proteinuria, hypoproteinemia, edema, hyperlipidemia. 3. Urinary tract infection: after the urinary system is infected by bacteria and viruses, it can cause the tension of urine to decrease, and the urine foam will not disappear for a long time. 4. Diabetes: diabetic patients in the urine of urine sugar, ketone body content is relatively high, so that the tension of urine decreased, the urine foam for a long time does not disappear. Urine foam for a long time does not disappear should be timely medical care, clear reasons for targeted treatment.