Normal urine can appear a small amount of foam, if there is a large amount of foam in the urine indicates that the composition of the urine changes, the following reasons are common: 1, diabetes mellitus: because diabetic urine contains high urinary glucose can lead to a large amount of foam in the urine, the patient is often accompanied by eating more, drinking more, increased urination, weight loss and other symptoms, it is recommended that you should go to the hospital to do a fasting blood glucose and urine routine examination can be a clear diagnosis. 2, urinary tract infection: caused by urinary tract infection in the urine can appear a lot of foam, such as cystitis, urethritis, etc., the patient is often accompanied by frequent urination, urinary urgency, urinary pain, etc., should go to the hospital to do the routine blood, urine routine examination can be diagnosed. 3, kidney disease: such as chronic nephritis, glomerulonephritis, etc., the urine appears to have an increase in the content of protein, which can also lead to foamy urine, it is recommended that you go to the hospital to do renal Ultrasound to clarify the cause of the disease.