The presence of foam in urine is not necessarily an abnormal phenomenon, foam may also appear in the urine of normal people, and needs to be analyzed in the context of specific situations. Human urine contains many inorganic and organic components, and foam may form after flushing due to the different tensions of various components. In general, if the body is healthy, no other abnormal symptoms are combined, and the urine composition index as well as various other indicators do not show any abnormalities, it can be left alone. However, if the patient has back pain, difficulty in urination, or abnormalities such as proteinuria or hematuria in the urine, clinical suspicion of glomerulonephritis, tubulointerstitial nephritis, immune nephritis and other diseases may be raised. Diabetes mellitus may be suspected if there is excessive drinking, polyphagia, polyuria and weight loss. The presence of foamy urine is not necessarily an abnormal symptom, but if combined with uncomfortable symptoms, it is necessary to promptly consult a urologist to identify different diseases and take appropriate treatment.