Whether the foam in proteinuria is present in morning urine or throughout the day depends mainly on the cause of proteinuria. If it is caused by physiological reasons, it may be in the morning urine; if it is caused by pathological reasons such as glomerulonephritis, it is usually throughout the day. In addition, the urine foam is also related to the amount of water to drink, even if the proteinuria, if you drink a lot of water, the amount of protein in the urine will be diluted, and at this time the foam in the urine may also disappear. 1. Physiological reasons: such as the intake of more high-protein foods may appear proteinuria, and because the morning urine is concentrated overnight and stored in the bladder and then excreted urine, so it may be due to the urine in the bladder for too long, the morning urine contains glucose, protein and other components of the more lead to the emergence of bubbles, but there is no foam in the urine during the day. 2. Pathological reasons: such as glomerulonephritis, nephrotic syndrome, etc., there may be a large amount of proteinuria, elevated protein content in the urine can lead to an increase in the urine foam, the foam is mostly fine, and lasts for a long time. Usually the foam in proteinuria is present throughout the day. If the patient has proteinuria or foam in the urine, it is recommended to go to the regular hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.