A small amount of foam can appear in normal urine, if a large amount of foam in urine indicates that the composition of urine has changed, the following common causes: 1, diabetes: because the urine of diabetic patients containing urine sugar is relatively high, can lead to a large amount of foam in urine, the patient is often accompanied by eating more, drinking more, more urine, weight loss and other symptoms, at this time it is recommended that you should go to the hospital, do fasting blood sugar and urinary routine 2, urinary tract infections: caused by urinary tract infections in the urine can appear a lot of foam, such as cystitis, urethritis, etc., the patient is often accompanied by frequent urination, urinary urgency, painful urination, etc., should go to the hospital to do routine blood and urine tests can confirm the diagnosis. 3, kidney disease: such as chronic nephritis, glomerulonephritis, etc., urine with increased protein content, can also lead to foamy urine, it is recommended to go to the hospital to do kidney B ultrasound to clarify the cause.