Loss of function of the left kidney fluid accumulation is not removed, it may affect the right kidney due to urinary tract infection and other reasons. When the left kidney has long-term fluid accumulation due to obstruction, it can cause atrophy and complete loss of renal function. In general, if the right kidney has normal function, the left kidney with loss of function needs to be resected. Without resection, the heavily hydronephrotic left kidney will form a burden in the retroperitoneum and will cause localized compression. Heavily hydronephrotic kidneys are also prone to rupture and bleeding due to trauma and other causes. On the other hand, hydronephrosis is prone to urinary tract infections, and the infection may spread to the right kidney, triggering impaired kidney function on the right side. Loss of left kidney function with fluid accumulation, it is recommended to seek medical treatment in time and standardize the treatment under the guidance of professional doctors.