Foamy urine may be related to the speed of urination, but also may be related to nephritis, cystitis and other diseases. 1. Urination speed: If the speed of urination is fast, it may lead to swirls between the urine, resulting in the phenomenon of foam in the urine, which is generally a normal physiological phenomenon. 2. Nephritis: the cause of nephritis is not clear, it may be related to bacterial and viral infections, genetic factors, autoimmune system disorders and other factors. Patients may have red urine, proteinuria, edema, high blood pressure and other symptoms, which may also lead to foam in the urine. 3. Cystitis: Cystitis is a disease of inflammatory lesions of the bladder, the cause of which may be related to bacterial infection, drugs, allergies and other factors. The main manifestations are frequent urination, painful urination, urgency, and hematuria in some patients, and at the same time, it may also make foam appear in the urine. If there is foam in the urine, it is recommended to go to the regular hospital for consultation and examination, to clarify the cause of the disease and actively treat it.