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2. Urinary Tract Infection (UTI) Slideshow Pictures
3. Urinary Incontinence in Women Slideshow Pictures

Medical Author:

Siamak T. Nabili, MD, MPH

Siamak T. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Kidney infection facts
• What is the function of the kidneys?
• Where are the kidneys located?
• What is a kidney infection?
• What are the causes of kidney infection?
• What are risk factors for kidney and urinary tract infection?
• Is screening recommended for UTI or kidney infection?
• What are the signs and symptoms of kidney infection?
• How is kidney infection diagnosed?
• What are different types of kidney infection?
• What are the common bacteria that cause kidney infections?
• What is the treatment for kidney infection?
• Are there foods I should avoid if I have a kidney infection?
• Can kidney infection be prevented?
• Patient Comments: Kidney Infection - Causes
• Patient Comments: Kidney Infection - Symptoms
• Patient Comments: Kidney Infection - Treatments
• Find a local Nephrologist in your town
• Kidney Infection Index

Kidney infection, or pyelonephritis, may be classified as uncomplicated, complicated, or chronic kidney infection (long-term).

A complicated kidney infection refers to severe involvement of the kidney, for example, abscess formation, enlarged kidney, or gas seen in the kidney by an imaging study, such as a CT scan. In these situations, the symptoms may be more severe and less responsive to usual treatments.

Chronic kidney infection may refer to recurring kidney infection that could be a result of a kidney stone obstructing the ureter or other structural abnormalities in the ureters (for example, vesicoureteral reflux, a condition in which urine is forced back up toward the kidneys). These conditions are usually associated with milder symptoms, but they may last longer.

The evaluation of complicated kidney infection and chronic kidney infection typically require a more thorough evaluation and more extensive testing such as CT scans and X-rays.

The most common bacteria responsible for kidney infection are Escherichia coli (E coli), which accounts for close to 80% of cases of kidney and urinary tract infections. Other common bacteria are Klebsiella, Proteus, Pseudomonas, Enterococcus, and Staphylococcus saprophyticus.

The most important component of treating kidney infection (as with any bacterial infection) is timely initiation of antibiotics under the directions of a health care professional. If kidney infection is diagnosed, then an empiric antibiotic (an antibiotic that would cover all likely bacterial organisms) is usually prescribed. A urine and blood sample will be taken and sent to a laboratory for analysis of any bacterial growth (urine culture and blood culture).

When a specific type of bacteria is isolated, antibiotics may then be changed to cover the particular bacteria. If the bacteria shows resistance (unresponsive) to the antibiotic that was initially prescribed, then the antibiotic is changed promptly to one that the organism is susceptible to in order to cure the kidney infection.

Home remedy with oral antibiotics and adequate water and fluid intake are usually sufficient for curing uncomplicated kidney infection and urinary tract infection. Nondrug home therapy with fluid intake, cranberry products, or acupuncture without antibiotics is not advisable for kidney infections.

However, if symptoms are severe (uncontrolled nausea and vomiting resulting in inability to take medications) or the infection is difficult to control with the routine oral remedies for kidney infection, then hospitalization may be required to receive intravenous antibiotics, intravenous hydration, and aggressive management of symptoms. In cases of complicated kidney infection hospitalization may also be necessary.

Self-medication for kidney infection is considered only in patients with mild, recurrent urinary infections. In individuals who are reliable and familiar with the symptoms of kidney infection, appropriate antibiotics prescribed to them in advance by their treating physicians may be started at the onset of their symptoms.