Yellow and foamy urine does not necessarily mean UTI. The yellow urine with foam is in most cases very much related to the physiological factors of drinking less water and concentrated urine. It is advisable to drink more water and urinate more often, if it improves, then it should not be a big problem. But if it still does not improve, it should be taken seriously, especially if the foam in the urine has been more, to rule out the possibility of nephritis, you can perform routine urine tests. If you are really suffering from nephritis, especially chronic nephritis, then it is possible to develop into uremic syndrome. The diagnosis of uremia is mainly based on the kidney function test. If the kidney function test reveals that creatinine and urea are significantly elevated, and this elevation is caused by chronic kidney diseases, such as chronic nephritis, diabetic nephropathy, hypertensive nephropathy, lupus nephritis, etc., when the creatinine exceeds 707μmol/L, then the patient is considered to be in the uremic phase.