Whether it is normal for foamy urine to disappear in 20 minutes depends mainly on its cause. If it is caused by physiological reasons, it may be normal; if it is caused by pathological reasons, such as nephritis, diabetes, etc., it may be abnormal. 1. Physiological reasons: due to the low surface tension of urine, foam is seldom formed. If foamy urine occurs, it may be caused by dietary factors, such as eating too much food with high protein content, which may lead to foamy urine, and may also lead to the disappearance of foamy urine more slowly, which is a normal phenomenon. 2. Pathological reasons: If the foamy urine often occurs and disappears slowly, it is usually considered that it may be caused by kidney disease, such as nephritis, proteinuria, which causes foamy urine. In addition, it may also be caused by diabetes mellitus, due to the patient’s high urine sugar, resulting in a decrease in the surface tension of the urine, thus generating bubbles. This condition is not normal. Foamy urine may also have other reasons, if the patient’s urine foam is recommended to 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.