With the spread of medical knowledge, we all have some knowledge about health. Among them is the urine, to distinguish the health status of the body. Some people panic when they find foam in their urine. Because he thinks that if there is foam in urine, it means protein urine; and if there is protein urine, it means that there is a problem with kidney function. So is this in fact true? Foamy urine is not the same as proteinuria. This is because the surface tension of normal urine is very low and bubbles are rarely formed, so foamy urine will not appear. However, if the body eats too much protein food and the body cannot absorb it completely, then there may be a part that is excreted through the urine, so that the urine is prone to the phenomenon of foam, but the foam will disappear quickly. Another situation is that if the normal urine contains some organic substances (glucose) and inorganic substances (mineral salts), it can make the tension of the urine stronger, and some foam can be produced due to the impact when urinating. But these bubbles will disappear quickly, if it is protein urine live, the bubbles will not disappear. The more foam does not mean that the proteinuria is more serious. This is because the appearance of foamy urine is only an indication of the body’s appearance, and it cannot be considered a symptom of a disease without professional examination, which means that there is only the possibility of proteinuria, and whether it is proteinuria or not, it is still necessary to do professional examination. The presence of proteinuria after a routine urine test in the hospital can only indicate that their kidneys are damaged. It should be noted that the occasional detection of protein “+” in urine does not necessarily indicate kidney damage, but should be combined with repeated urine tests and kidney function tests and, if necessary, a kidney biopsy to determine the extent of kidney damage. There is no direct and necessary connection between foamy urine and proteinuria, and it cannot be directly inferred as a symptom of kidney failure. Some people with severe kidney disease do not necessarily have a lot of foam in their urine. Some people who urinate frequently and urgently may not have a lot of foam, or even no foam, but in fact other parts of the kidney have become diseased. Therefore there is no scientific basis to judge whether the disease is serious or not by the single amount of foam.