Acute pyelonephritis is the germ infection of the kidney and it is caused upstream. Symptoms include high fever, dysuric complaints, severe pain in the inflamed kidney. The diagnosis includes the clinical examination, microbiological tests of blood and urine as well as ultrasound of the kidneys. Ultrasound may show distension of the pelvic-calyceal system which may be caused by a stone (discussed elsewhere) or there may be no obvious cause of obstruction. In specific cases of severe symptoms and very high fever, hospitalization is deemed necessary to receive intravenous antibiotics until the patient is fever-free, where he continues with oral treatment at home.