May 13, 2019

Urinary Tract Health, From Bladder to Kidney Infections

What women should know

Illustration of a urinary tract infection

Your kidneys are part of your urinary tract – along with your bladder and the tubes that connect these organs (the urethra and ureter). The main purpose of your kidneys is to clean the waste from your blood. The good news is that kidney infections aren’t common. They’re essentially a much more serious urinary tract infection, urologist Sandip Vasavada, MD, explains.


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“Normally the bacteria that would cause a kidney infection is flushed out by the flow of your urine,” says Dr. Vasavada. “However, if your pee is stopped by structural abnormalities in the kidneys, or the tubes are compressed, there can be a back flow of urine from the bladder to the kidneys and the bacteria can gain a foothold and cause infection.

Who is susceptible to a kidney infection?

Patients who have a kidney infection are usually in advanced age, or they have an issue that compromises their health, such as kidney stones, an obstruction, an anatomic abnormality or diabetes. “More often, women have a urinary tract infection that they treat, which keeps it from progressing to a kidney infection,” says Dr. Vasavada. “But bladder infections very rarely progress to kidney infections.”

You will be pretty sick if you have a kidney infection, and it’s important that you seek treatment right away.

Symptoms of a bladder infection are urgency and frequency in using the bathroom and burning with urination, while symptoms of a kidney infection are much more severe and include:

  • Fever and flu-like symptoms.
  • Lower back or side pain. This can be on the left or right side of your back depending on which kidney is infected. “It may feel like you were hit in the back with a baseball bat,” Dr. Vasavada says.
  • Nausea and vomiting.
  • Urine that is cloudy, has blood in it and is foul smelling.
  • A general sense of malaise.

How is it diagnosed?

Tests to determine if you have a kidney infection include an ultrasound, X-ray or computed tomography scan (CT) scan. Also you will typically have an elevated white blood cell count and an ongoing fever. Your urine will be tested and for nitrites, which show the presence of bacteria.

How can I prevent a urinary tract infection?

Dr. Vasavada stresses practicing good urinary tract health, which means:

  • After using the bathroom, wipe from front to back to avoid moving bacteria back into the urinary tract.
  • Drink plenty of water.
  • Monitor for developing infections following sexual relations and practice good hygiene.
  • Cranberry pills or cranberry juice may help (although research is not conclusive on this).
  • For women who are post-menopausal, vaginal estrogen may lower susceptibility to infection by changing the vaginal acidity (pH), which may prevent bacteria from overgrowing near the urinary tract.

Kidney infections are treated with antibiotics. Most antibiotic treatments will last for a minimum of 7 to 14 days, and it’s important that you take the full prescription to ensure that all bacteria are killed.


Dr. Vasavada says if you suspect a kidney infection, you should go to an urgent care, make an appointment with your general doctor as soon as you can, or go to the emergency department.

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