Pyelonephritis is an ascending urinary tract infection that has reached the pyelum (pelvis) of the kidney (nephros in Greek).
Pyelonephritis is an inflammation of the kidney and upper urinary tract that usually results from noncontagious bacterial infection of the bladder (cystitis). Pyelonephritis is a serious bacterial infection of the kidney that can be acute or chronic. It is a form of nephritis. It can also be called pyelitis. Pyelonephritis most often occurs as a result of urinary tract infection, particularly in the presence of occasional or persistent backflow of urine from the bladder into the ureters or kidney pelvis (vesicoureteric reflux). Pyelonephritis can be further classified is acute uncomplicated pyelonephritis (sudden development of kidney inflammation) and Chronic pyelonephritis (a long-standing infection that does not clear) Although cystitis (bladder infection) is common, pyelonephritis occurs much less often. The risk is increased if there is a history of cystitis, renal papillary necrosis, kidney stones, vesicoureteric reflux, or obstructive uropathy.Signs and symptomsIt presents with dysuria (painful voiding of urine), abdominal pain (radiating to the back on the affected side) and tenderness of the bladder area and the side of the involved kidney ("renal angle tenderness"). In many cases there are systemic symptoms in the form of fever, rigors (violent shivering while the temperature rises), headache and vomiting. In severe cases, delirium may be present.TreatmentTreatment of acute pyelonephritis may require hospitalization if the patient is severely ill or has complications. Therapy most often involves a two- to three-week course of antibiotics, with the first few days of treatment given intravenously.A kidney infection is treated with an appropriate antibiotic taken for several weeks. Anatomic abnormalities may need to be surgically treated. Antibiotics will usually clear the infection. An antibiotic is usually prescribed straight away if a kidney infection is suspected, even before the result of the urine test is known. Some bacteria are resistant to some antibiotics. Painkillers such as paracetamol or ibuprofen ease pain and reduce a high temperature (fever). Stronger painkillers may be needed if the pain is more severe. Due to the high mortality rate in the elderly population and the risk of complications, prompt treatment is recommended. Drinking cranberry juice prevents certain types of bacteria from attaching to the wall of the bladder and may lessen the chance of infection.
