Hydronephrosis with nausea can be caused by various reasons, so alleviating nausea symptoms requires specific analysis based on the specific cause. Patients with hydronephrosis often seen in hospital beds are mostly those with ureteral stones. When the stone is lodged in the ureter, the patient will experience an obstruction of urine outflow, leading to hydronephrosis. Moreover, a stone stuck in the ureter can cause renal colic, manifested as back pain, and may also be accompanied by symptoms of nausea and vomiting. In such cases, treatment methods depend on the size of the stone; if the stone is relatively small, it can often be passed naturally with increased water intake and conservative treatment. If the stone is large, it generally requires surgical removal. Hydronephrosis can also result from prolonged obstruction leading to impaired kidney function and uremia. In these situations, it's usually necessary to promptly relieve the urinary obstruction, maintain urethral patency, and, if the patient has elevated blood creatinine levels, employ dialysis or other methods to bring creatinine back to reasonable levels.