Pyelonephritis is a condition of the kidneys in which the kidneys cease to function because of a bacterial infection. This is a very serious disease because it can cause the kidneys to shut down completely and increase blood toxicity. The infection may also enter the blood stream and spread to other parts of the body. In pregnant women, pyelonephritis can cause early labor. It is one of the most common causes of premature labor. The infection is usually located within the renal pelvis but may soon spread to other parts within the renal parenchyma. The infection is caused due to the same bacteria that is responsible for bladder and urinary tract infections. Some of the most common bacteria associated with this condition include escherichia coli, Klebsiella spp, Enterococcus spp and Proteus spp. Some people may experience recurrent pyelonephritis and this could lead to chronic pyelonephritis, which is extremely dangerous and may cause permanent damage to the kidneys.
There are two main kinds of pyelonephritis conditions - acute and chronic. As the name suggests, the acute pyelonephritis has a sudden onset while the chronic condition occurs over a period of time and may be associated with recurrent cases of acute pyelonephritis. The presentation of the two types may be similar to each other.