Inflammation of the renal pelvis and Often also of kidney tissue, usually subsequent to inflammation of the urinary tract, such as inflammation of the bladder (cystitis). Pyelitis occurs particularly as a result of restriction of the flow of urine, by kidney stones for example, tumours of the renal pelvis or pregnancy. Inflammation of the bladder can also lead to pyelitis in conditions such as urine retention resulting from an enlarged prostate or nerve failure. Chronic pyelitis is usually caused by an anatomical abnormality of the urinary tract and/or restricted urinary flow. In severe cases the kidneys can be damaged to the extent of causing kidney failure, associated with uraemia. The symptoms of pyelitis include fever, back pain and pain associated with urination. In chronic cases the predominant symptoms are exhaustion and loss of appetite. Treatment is by high fluid intake and antibiotics. The root cause of the inflammation should also be sought. Contrast X-rays and sonographic examination of the kidneys are also possible.