The floating pinpoint foam on top of the urine may be caused by physiological reasons such as concentration of urine, and may also be caused by pathological reasons such as cystitis, nephrotic syndrome, diabetes and other disease factors. 1. Physiological reasons: drinking too little water leads to urine concentration, prolonged urinary holding lead to urinary urgency, etc. may appear in the urine foam, this time the size of the foam varies, is a normal phenomenon, do not need special treatment. 2. Pathologic causes: (1) cystitis: due to bacterial reproduction, the composition of urine is prone to change, there will be white blood cells, bacteria and a small amount of protein in the urine, which may produce foam. (2) nephrotic syndrome: there will be a large amount of proteinuria, elevated protein content in the urine can lead to increased foam in the urine, the foam is mostly fine and lasts for a long time. (3) Diabetes mellitus: diabetes mellitus can lead to elevated glucose and ketone bodies in the urine, glucose for the abnormal organic matter appearing in the urine, ketone bodies will change the pH of the urine, both of which may lead to the appearance of foam in the urine. Urine floating on top of the needle tip small foam does not dissipate may also have other reasons, it is recommended that patients go to the regular hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.