In most cases, a small amount of foam in the urine is normal. However, if there is a sudden increase in the amount of urine foam, accompanied by back pain and fatigue and other obvious symptoms, it is necessary to consult a doctor in a timely manner for relevant examinations. Under normal circumstances, there is no foam in the urine, and even if there is a small amount of foam, it will disappear quickly. If you suddenly find a large amount of foam in the urine, half an hour does not disappear, indicating that more protein is excreted in the urine. There is also protein in the urine under normal circumstances, but the amount is very small, mainly due to a small amount of leakage from the glomeruli. When there is inflammation in the glomeruli, the function of the kidneys decreases, resulting in increased leakage of protein, so when the body excretes urine with high protein content, a lot of foam will be produced.