The symptoms of acute nephritis are mainly manifested as acute nephritic syndrome, that is, hematuria, proteinuria, edema, hypertension, and transient acute kidney injury. Hematuria is a symptom present in almost all cases of acute nephritis, but it is mostly microscopic hematuria, meaning during examination, the routine urine analysis shows positive occult blood, or red blood cells are found in the urinary sediment. About 40% of the patients may exhibit gross hematuria, where the urine color appears like wash-water or may be bright red, deep tea-colored, and so on. The second symptom is proteinuria, which is also often indicated by a positive urine protein test during routine checks. The third symptom is edema, an early symptom of acute nephritis. Mildly, it presents as swelling of the eyelids in the morning and can spread to the whole body if severe. The fourth symptom is hypertension, with about 80% of patients showing a moderate increase in blood pressure. In severe cases, patients might experience oliguria, with urine output less than 400ml/d, accompanied by transient mild increases in blood creatinine and urea nitrogen, indicating acute kidney injury. This condition is mostly self-limiting, and many patients can recover within a few weeks.