The kidneys have a very strong compensatory ability. In the early stages of hydronephrosis, the amount of fluid may not be large, or the duration may not be long, and usually, the patient may have no symptoms. Hydronephrosis is often discovered during health examinations or through ultrasound or CT scans performed during hospital stays.

Of course, if the hydronephrosis persists for too long and the volume is very large, the patient can gradually feel discomfort or a distended sensation in the lower back or upper abdomen. Moreover, if the hydronephrosis is caused by kidney stones, the patient often experiences severe back pain, and there might even be visible blood in the urine.

Hydronephrosis can also lead to symptoms of urinary tract infections such as frequent urination, urgent urination, and painful urination. Prolonged hydronephrosis can lead to a decline in kidney function, resulting in symptoms like fatigue, loss of appetite, and poor overall health. Therefore, it is crucial for patients to undergo regular ultrasound examinations of the kidneys to detect hydronephrosis early.