Urine always foam may be physiological phenomenon or pathological phenomenon such as diabetes, kidney disease, urinary tract infection and other causes. 1. Physiological phenomenon: the body in normal circumstances, the urination process will produce a small amount of foam, but will soon disappear, this situation is considered physiological. 2. Diabetes: patients with diabetes, sugar or ketone bodies increase in the urine, resulting in changes in urine pH, changes in urine surface tension, the foam in the urine will increase after urination, and there is always foam in the urine after each urination. 3. Kidney disease: such as membranous nephropathy, mild lesion nephropathy, membranoproliferative glomerulonephritis and other kidney disease patients, will lead to increased protein content in the urine, urine surface tension changes, urine foam is increased, and every time you urinate there is foam. 4. Urinary tract infections: patients with urinary tract infections, the urine will produce bacteria, increased gas content in the urine, can also be manifested as foamy urine. There are more reasons for the foam inside the urine, it is recommended that the patient to the hospital in time to identify the cause, follow the doctor’s instructions for treatment.