High blood sugar, urine may appear foam. There are two reasons for foam in urine with high blood sugar: the first one is that blood sugar will produce some foam in the process of passing through the urine discharge, and the second one is that poor blood sugar control for too long, especially in more than five years, has led to diabetic nephropathy. And many diabetic nephropathy have urine protein, and urine protein will foam a lot in the process of flushing through the urine. Therefore, if blood sugar is elevated and there is foam in the urine, it is recommended to perform routine urine examination. If the foam in urine is only caused by elevated blood sugar, it is necessary to strictly control blood sugar to prevent the development of diabetic nephropathy. Once diabetic nephropathy develops, it is irreversible and the kidney disease will gradually progress and eventually develop into renal failure. If there is an increase in urine protein caused by foam, you can apply drugs to reduce urine protein, such as valsartan capsules, Benadryl tablets and so on. After the urine protein is well controlled, the kidney function can progress more slowly.