Pyelonephritis is inflammation of the kidney. Bacterial infection is a common cause. Inflammation may affect one or both kidneys. Symptoms most often include fever and the side of the body hurting between the ribs and the hips. Other symptoms include nausea, a burning feeling when urinating (peeing), and unusually frequent urination. Complications may include pus around the kidney, sepsis (an infection that is out of control, often of the blood), or kidney failure. This can also happen in pets and other animals.
Usually, antibiotics are used to treat the infection. In some cases, a stay in hospital may be required. Urinating after sex and drinking a lot of water may prevent it.
↑"Antibiotic therapy for acute uncomplicated pyelonephritis in women. Take resistance into account". Prescrire International. 23 (155): 296–300. December 2014. PMID25629148.