Whether diabetes-induced hydronephrosis is dangerous or not depends on the degree of hydronephrosis, the presence or absence of infection, and the damage of renal function, etc. If the degree of hydronephrosis is mild, there is no infection, renal function has not been impaired, and the treatment is timely and effective, then it is not dangerous, and on the contrary, it is more dangerous. Patients with diabetic hydronephrosis should actively cooperate with doctors for treatment, such as using glucose-lowering drugs such as acarbose or insulin to control blood glucose, and sodium bicarbonate can be used to alkalize urine with uric acid stones, and surgery can be performed if necessary. For the fluid accumulation degree is light, not accompanied by urinary tract infection, no combination of renal function impairment and other conditions of patients after active treatment prognosis is better, generally not dangerous. If the degree of hydronephrosis is deep, combined with acute pyelonephritis, with long-term obstruction caused by renal dysfunction and other conditions, then it is more dangerous. Diabetic patients diagnosed with hydronephrosis should actively cooperate with doctors for treatment, which can help improve the prognosis.