The primary cause of acute nephritis is related to antigen-antibody mediated immune damage. This means that when patients with acute nephritis are infected by streptococci, certain components within the streptococci can act as antigens and bind to corresponding antibodies produced in the body, forming immune complexes. These immune complexes circulate through the bloodstream and eventually deposit in the glomeruli. When the complement system is activated, inflammatory cells infiltrate, ultimately leading to the development of acute nephritis. Acute nephritis is a common group of primary glomerular diseases, characterized by a sudden onset, with hematuria, reduced urine output, proteinuria, edema, and hypertension as its most significant features. Once acute nephritis occurs, bed rest is usually required, along with active treatment. After treatment, most patients with acute nephritis can recover fully, with few recurrences.