Holding urine will not cause uremia. Holding urine may lead to bladder fullness, and after a long time, it might cause dilation of the ureters, but it will not lead to uremia. Uremia is caused by renal insufficiency or end-stage renal failure, characterized by significantly increased creatinine and urea nitrogen in the patient's body, with reduced urine output or even anuria. Once uremia is diagnosed, it generally requires hospitalization for dialysis treatment, which involves removing toxins from the body through dialysis. Additionally, it is advised to consume nutritionally rich foods in daily life.