The clinical manifestations of the disease vary widely, with the milder cases being “subclinical”, i.e., without specific clinical manifestations except for abnormal laboratory tests; the more severe cases may be complicated by severe circulatory congestion, hypertensive encephalopathy, and acute renal failure. Typical cases 1. History of prodromal disease: About 10 days before the onset of the disease, there is often a history of streptococcal prodromal infection such as upper respiratory tract infection and tonsillitis; for those with skin impetigo as the prodromal history, the prodromal period is slightly longer, about 2 to 4 weeks. 2.Oedema: Initially, eyelids and face are predominant, gradually descending to the extremities in a non-depressed manner; combined ascites and pleural effusion are rare. 3. Urine volume: The decrease in urine volume is parallel to edema, and the less urine volume, the more edema. The standard of little urine is <400ml per day for school-age children, <300ml for preschool children, <200ml for infants and toddlers or less than 250ml/m2 per day; the standard of no urine is <50ml/m2 per day. Hematuria: Hematuria: it is often the first symptom of the disease, and almost all patients have hematuria, of which the rate of visual hematuria is about 40%; it turns to microscopic hematuria after 1 to 2 weeks. The majority of patients with mild disease do not have hematuria. 5. Proteinuria: almost all patients have positive urine protein, but proteinuria is generally not serious, between 0.5 and 3.5 g/d. 6. Hypertension: seen in 70% of cases. Hypertension is seen in 30% to 80% of cases, due to water and sodium retention and blood volume expansion, generally mild or moderate increase. In most cases, the blood pressure decreases to normal after 1 to 2 weeks with diuresis, but if it does not decrease, the possibility of an acute attack of chronic nephritis should be considered. Different age groups have different criteria for hypertension: school-age children ≥ (130/90mmHg); preschool children ≥ (120/80mmHg); infants and children ≥ (110/70mmHg) for hypertension. 7, renal impairment: often have transient azotemia, blood creatinine and urea nitrogen mildly elevated, after a few days of diuresis, azotemia can return to normal. In a few patients, acute renal failure may occur; 8. Laboratory tests: transient anemia, elevated anti-chain "O", elevated ESR, decreased complement, etc.