Acute nephritis usually becomes chronic after 3 months. The full name of acute nephritis is acute glomerulonephritis, mostly caused by Streptococcus haemolyticus infection, this disease is self-limiting, generally in 8 weeks basically healed, the prognosis is very good, a few patients can be delayed until half a year, or even a year, urine test, blood pressure only gradually returned to normal, this time is also considered clinically cured. In general after more than 3 months, there is still urine protein, urine occult blood or blood pressure is still very high, consider the possibility of acute nephritis into chronic nephritis, which is a poor prognosis. If necessary, perform nephroporation to clarify the specific pathological type. Apply hormone or immunosuppressant to treat if necessary. If the pathological type is poor, the possibility of cure is low. It is important to control the urine protein quantification and blood pressure, because these two are the factors of renal function aggravation.