Pyelonephritis is inflammation of the kidney. Bacterial infection is a coomon cause.[1] 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.[2] Other symptoms include nausea, a burning feeling when urinating (peeing), and unusually frequent urination.[2] Complications may include pus around the kidney, sepsis (an infection that is out of control, often of the blood), or kidney failure.[1] This can also happen in pets and other animals.
Usually, antibiotics are used to treat the infection.[3][4] In some cases, a stay in hospital may be required. Urinating after sex and drinking a lot of water may prevent it.[5]