Rapidly progressive nephritis, also known as rapidly progressive glomerulonephritis (RPGN), was first proposed by Ellis in 1942. It belongs to acute nephritic syndrome clinically. It is a group of glomerulonephritis with similar clinical manifestations and pathological changes but different causes. The clinical manifestations are rapid progression of the disease, rapid development of proteinuria and hematuria, and renal failure within a few months or even weeks. Glomerulonephritis with a poor prognosis. The pathological changes of this disease are cell proliferation and fibrin deposition in the glomerular capsule, so it is also called crescentic nephritis. Although the incidence of this group of diseases is low, timely diagnosis and adequate treatment can effectively change the prognosis of the disease, therefore, it has attracted great clinical attention.