Pyelonephritis is a type of
urinary tract infection (
UTI) that develops when bacteria spread from the bladder to the kidneys. A serious health problem, pyelonephritis affects more women than men for reasons that are not yet well understood. Although pyelonephritis in men is not as common, it can be very serious when it does occur.
Understanding the Urinary Tract
The urinary tract consists of the kidneys, ureters, bladder, and urethra. The kidneys are two bean-shaped organs located below the ribs toward the middle of the back. The role of the kidneys is to:
- Help control blood pressure
- Make red blood cells
- Keep bones strong
- Remove extra water and wastes from the blood
- Convert the wastes to urine.
The wastes in your blood come from the normal breakdown of active muscle and from the food that you eat. Your body uses the food for energy and self-repair and sends the wastes to the blood. If your kidneys did not remove these wastes, the wastes would build up in the blood and damage your body.
Narrow tubes called ureters carry urine from the kidneys to the bladder, which is an oval-shaped chamber in the lower abdomen. Like a balloon, the bladder's elastic walls stretch and expand to store urine and flatten back together when the urine is emptied through the urethra outside of the body.
Bacteria usually cause pyelonephritis. The most common type of bacteria that causes pyelonephritis is Escherichia coli (E. coli), which can live in the digestive tract, in the vagina, or around the urethra. In most cases, these bacteria enter the urethra and travel to the bladder and kidneys. However, your body will usually remove the bacteria and you will not have symptoms.
Risk Factors for Pyelonephritis
Doctors can seldom explain why one person will get pyelonephritis and another person will not. However, pyelonephritis research has shown that people with certain risk factors are more likely than others to develop pyelonephritis. A risk factor is anything that increases a person's chance of developing a disease.
Pyelonephritis risk factors include:
- Infections in the bladder (see UTI Risk Factors)
- Use of a catheter to drain urine from the bladder
- Use of a cystoscope to examine the bladder or urethra
- Surgery on the urinary tract
- Conditions such as prostate enlargement and kidney stones
- Gender and age (females and the elderly are much more likely to get pyelonephritis).
Pyelonephritis symptoms can include:
- Pain or stinging when you pass urine
- Frequent or intense urges to urinate, even when you have little urine to pass
- Back, side, or groin pain
- Urine that smells bad or looks milky, cloudy, or reddish in color
- Nausea and vomiting
- Fever or chills.
Not everyone with pyelonephritis will have symptoms, especially in the elderly or debilitated. However, they may experience symptoms such as: an altered mental state, fever, or low
blood pressure. Children are more likely to have a fever and no other symptoms of pyelonephritis, which may lead to a misdiagnosis.
Diagnosing Pyelonephritis
In order to make a pyelonephritis diagnosis, doctors will ask you a number of questions, perform a physical exam, test your urine, and may recommend imaging tests.
Urine Tests
Your urine will be checked under a microscope for bacteria and infection-fighting cells. Your doctor may also order a urine culture, in which bacteria from the urine are allowed to grow in a lab dish. This will allow your doctor to identify the type of bacteria that you have and the type of antibiotic that you need for treatment.
Imaging Tests
Doctor may use x-rays, sound waves (ultrasound), or a computed tomography (CT) scan to view your kidneys, ureters, and bladder. These pictures can show stones, blockages, and swelling.
Once it is determined that your symptoms have been caused by pyelonephritis, your doctor will prescribe an antibiotic, which will kill the bacteria causing pyelonephritis. The antibiotic prescribed for your pyelonephritis will depend on the type of bacteria that are found.
For uncomplicated pyelonephritis, treatment will usually last for 2 weeks. Be sure to follow your doctor's instructions carefully. Also, let your doctor know if you are allergic to any medications. Some patients may need to stay in the hospital to receive antibiotics, and other people may need surgery if the kidneys, ureters, or bladder is causing pyelonephritis.
Complications From Pyelonephritis
Untreated or recurrent pyelonephritis can lead to chronic pyelonephritis, scarring of the kidneys, and permanent kidney damage.
