The diagnostic criteria for azotemia include a decrease in glomerular filtration rate to 50-25 mL/min, blood urea nitrogen is between 9-20 mmol/L, and blood creatinine is between 178-445 μmol/L. Patients will have generalized weakness, lumbar discomfort, varying degrees of anemia, and increased nocturnal urination, with nocturnal urine volume reaching 750mL or more. Patients may also have symptoms of gastrointestinal discomfort, such as nausea, which is more pronounced when waking up early in the morning, as well as abdominal distention and loss of appetite. Azotemia is a stage of chronic renal insufficiency, and when azotemia progresses further, it becomes uremic syndrome.