The full name of acute nephritis is acute glomerulonephritis. This disease mainly occurs in children and is often preceded by an infection, such as an upper respiratory tract infection or a skin infection. Typical clinical manifestations of acute glomerulonephritis include sudden hematuria, proteinuria, edema, hypertension, and some patients may exhibit transient azotemia. The severity of the condition varies among patients, with severe cases presenting as oliguric acute renal failure. Acute pyelonephritis, on the other hand, is a type of urinary tract infection. Its main clinical symptoms are fever, chills, frequent urination, urgent urination, painful urination, difficulty urinating, and may also include nausea, vomiting, headache, and general body aches. Its diagnosis is mainly based on the presence of positive urinary leukocytes in the routine urine test, and a clean-catch midstream urine culture greater than 100,000 per milliliter.