When there are bubbles during urination, then the possible causes: First, when the urine is concentrated, there can be more bubbles. Because of the concentrated state, the solute concentration component of urine is higher, and the shock with water during urination can produce more bubbles, mostly accompanied by deepening of urine color, usually without urinary tract irritation symptoms. Second, the urine contains more protein, and more bubbles can also appear. The foam is fine and lasts for a long time. It is common in patients with nephritis or nephrotic syndrome, and more protein is seen in routine urine examination. Thirdly, patients with elevated urine sugar can also have increased foam and need further blood sugar testing to rule out diabetes. Fourth, patients with urinary tract infections, urine containing more white blood cells, pus cells and red blood cells, etc., can cause increased foam. Most of them have urinary tract irritation symptoms, such as urinary frequency, urinary urgency, painful urination, etc. It is necessary to conduct routine urine tests to further confirm the diagnosis.