Acute nephritis has the following characteristics:

First, patients with acute nephritis often have a history of a precursor upper respiratory tract infection. After catching a cold, patients may develop hematuria, proteinuria, or anuria.

Second, patients with acute nephritis will experience a decrease in complement C3 in the blood. After recovery from acute nephritis, complement C3 can restore itself.

Third, acute nephritis is self-limiting; generally, the patient's condition will gradually improve over three to four weeks, and recovery can be complete after eight weeks. However, a very small number of patients might experience prolonged illness, evolving into chronic nephritis.

Fourth, the pathological characteristic of acute nephritis is diffuse proliferation of capillary endothelial cells, which is a manifestation of pathological damage to the glomeruli.