Generally, acute nephritis will change to chronic after more than 1 year. Acute nephritis is caused by β-hemolytic streptococcal infection, and the pathological type is intracapillary hyperplasia. The prognosis is relatively good, and most patients will experience diuresis and swelling reduction within 4 weeks, blood pressure drops to normal, and urine protein and urine occult blood turn negative on urine examination. In a minority of patients, microscopic hematuria or microscopic urine protein may be delayed for six months or even a year before gradually disappearing. In about 10% of patients, the urinalysis may still be abnormal after 1 year, which may be urinary occult blood, urine protein or the presence of hypertensive symptoms, suggesting that the patient may be transformed from acute nephritis to chronic nephritis. In this case, it is recommended to perform renal puncture to clarify whether the pathological type has been transformed before deciding on the next treatment plan.