Proteinuria does not cause foamy urine every time. Proteinuria causes foamy urine when there is more protein in the urine. If the urine protein is relatively small, the urine may not appear foamy. And proteinuria usually has no obvious symptoms in the early stages, and urine foam usually appears in the middle and late stages. Proteinuria is when there is too much protein in the urine. When there is too much protein in the urine, it can lead to a lot of foam that does not easily dissipate when urinating. However, in the early stages of proteinuria or when the amount of protein in the urine is low, there will not be a lot of indispersible foam in the urine. So proteinuria does not have foam in the urine every time. Proteinuria is usually associated with impaired kidney function and is usually accompanied by symptoms such as low back pain, lower limb edema and facial edema. Patients are advised to go to the hospital for urine examination, renal function test, blood test, etc. to make a clear diagnosis.