Foamy urine is a normal phenomenon in some older people, but should also be alert to pyelonephritis, diabetes and other diseases. 1. Normal phenomenon: some of the elderly urinary urgency, can be due to increased urination speed and provoke a large number of foam, can be manifested as foamy urine. It is worth noting that the duration of foamy urine is short, and should be distinguished from pathological factors. 2. Pyelonephritis: the reason why pyelonephritis can cause foamy urine is mainly related to the increase in the content of red blood cells and white blood cells in the urine of the patient, which leads to changes in the composition of urine. Pyelonephritis is associated with pathogenic microbial infection, urinary tract obstruction, etc. Patients may also be accompanied by fever, urinary frequency, back pain and other symptoms. 3. Diabetes mellitus: the cause of diabetes mellitus is still unclear, may be related to genetic factors, autoimmune system defects. Diabetic patients can be due to increased sugar or ketone bodies in the urine, changes in urine pH, prompting changes in the surface tension of the urine and foamy urine. Diabetic patients are also prone to other symptoms such as excessive drinking, eating, urinating, and weight loss. It is recommended that older people with foamy urine or other symptoms should seek medical attention in order to identify the disease and then follow the doctor’s instructions for treatment.