A ring of foam floating on the urine is generally referred to as the appearance of foamy urine, indicating the presence of protein in the urine. It can be caused by physiological factors such as strenuous exercise and low water intake, or pathological factors such as glomerulonephritis and urinary tract infections. 1. Physiological factors: urination speed is too fast, resulting in urine impact on the surface of the liquid, air and urine mixing to produce a large number of bubbles. Usually drink less water, the body is not enough water, the urine is concentrated, the other components of the urine relative increase, can also produce foam. 2. Pathological factors: such as various types of primary glomerulonephritis, secondary glomerulonephritis, urinary tract infections and other reasons, the occurrence of renal lesions leading to protein filtration from the kidneys into the urine, resulting in proteinuria. This situation should be timely to the hospital, improve the relevant examination to clarify the cause of the disease, under the guidance of the doctor symptomatic treatment.