When Does a UTI Turn into a Kidney Infection?


When Does a UTI Turn into a Kidney Infection?

written by Margaret A Spera, NP, APRN Written by Margaret A Spera, NP, APRN
Margaret A Spera, NP, APRN

Margaret A Spera, NP, APRN

Margaret Spera is a Connecticut-based nurse practitioner. She has worked in hospital settings, family practices and senior care facilities for over 40 years.

Read more posts by this author.

August 13, 2020 Read Time - 11 minutes

How Do You Know When a UTI Becomes a Kidney Infection?

When you do not see a doctor, a urinary tract infection can swiftly turn into a kidney infection, which can be very serious to your long-term health.

Urinary tract infections are one of the most common types of infection, second only to respiratory infections. They account for over 8.3 million visits to hospitals and health care providers each year. An untreated UTI may lead to a kidney infection, this is a potentially life-threatening condition.

Who do UTIs Affect?

UTIs are most common in women, occurring in about 1 in every 2 women at some point in their lives. Male urinary tract infections are less common, only occurring in about 12% of men at some point in their lives.

How Serious is a UTI?

Urinary tract infections can be painful and uncomfortable, but they ultimately don’t pose a serious threat to your health as long as you seek medical treatment as soon as possible.

Read on to learn more about when urinary tract infections turn into kidney infections, the differences between the two, and what you can do to properly treat and prevent them.

Read: Get UTI Treatment Online

Understanding Your Urinary Tract

Your urinary tract, or urinary system, comprises several different organs designed to extract, hold, and transport waste from your system in the form of urine. The main organs involved in the urinary system include:

  • The kidneys: These two organs sit on each side of your body, generally around the waist. They filter out excess water and waste from your blood to create urine.
  • The ureters: These two thin tubes run between the kidney and bladder, transporting urine to the bladder.
  • The bladder: This organ stores urine until it reaches a certain level, at which point you feel the need to pee. The body voluntarily contracts the muscles that line the bladder to urinate.
  • The urethra: This thin tube connects the bladder to the outside of the body. When you urinate, a muscle called the urinary sphincter relaxes as your bladder contracts to remove urine from your body.

Urinary tract infections happen when bacteria infect any part of your urinary system, but they are most common in your lower urinary tract, comprising the urethra and bladder.

What Causes Urinary Tract Infections

Urinary tract infections are most commonly caused by the bacteria Escherichia coli, which you might know as simply E. coli.

These bacteria are responsible for about 90% of all uncomplicated urinary tract infections. E. coli are found in the colons of humans and animals and in their fecal waste. When E. coli or other bacteria end up in the urethra, they cause a urinary tract infection.

There are other types of bacteria also known to cause UTIs. According to a study by The National Center for Biotechnology Information the most common bacteria to cause UTIs are:

  • Escherichia coli (E Coli)
  • Klebsiella pneumoniae
  • Streptococcus spp. (separated apart from Streptococcus D group), Staphylococcus epidermidis, Pseudomonas aeruginosa, and Enterococci were each found to be the third pathogens in different periods during the two-year study.

Infections can also be caused by:

  • Kidney stones, enlarged prostates, and other conditions that obstruct the urinary tract, preventing proper emptying of urine from the body
  • Spinal cord injury and other conditions that prevent you from properly emptying your bladder
  • Menopause or medications that alter the hormones in your body, thus changing the bacterial environment in your urinary tract system
  • Any condition that suppresses the immune system (HIV/AIDS, diabetes, chemotherapy)
  • Certain sexually transmitted infections, including chlamydia, herpes, gonorrhea, and mycoplasma

In rare cases, a virus or fungus can cause UTIs.

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Why Are Women More Likely To Get A UTI?

The reason that women get urinary tract infections more often is due to their anatomy. Their urethras are much shorter than men’s urethras, allowing the bacteria to reach the bladder easier. A woman’s urethra is also closer to her anus, making it easier for the bacteria to enter the urinary system.

Through improper wiping, sexual intercourse, and even toilet backsplash, E. coli can potentially end up in your urinary system.

Symptoms of Urinary Tract Infections

The symptoms of a basic urinary tract infection often include:

  • Dark, cloudy urine that may appear red or pink from blood
  • Painful or burning urination, a condition known as dysuria
  • An urgent and frequent need to urinate
  • A small amount of urine when you do go to the bathroom
  • Urine that smells bad
  • A mild fever that stays under 101 degrees Fahrenheit
  • Chills and malaise (feeling ill and unwell)
  • Pain in the lower abdomen
  • Pain and pressure in the pelvis

Read: What to do if you have a Urinary Tract Infection

Symptoms of Kidney Infections

Where does it hurt when you have a kidney infection? Many basic symptoms of kidney infections are similar to those of urinary tract infections, particularly:

  • the painful, burning urination
  • increased and urgent urination
  • and cloudy urine

However, once the infection has completely spread to the kidneys, kidney infections (pyelonephritis) may exhibit more serious symptoms and signs of severe illness, including:

  • Pain in your back and flanks
  • Chills and shaking
  • A fever that exceeds 101 degrees Fahrenheit
  • Nausea
  • Vomiting
  • Confusion, particularly in more elderly patients
  • More intense feelings of general illness

If you are experiencing symptoms of a kidney infection seek medical attention immediately. The sooner you receive treatment the more likely you are to prevent long term damage and recover faster.

UTI Kidney Infection

It’s important to treat your UTI as soon as possible with a combination of doctor prescribed antibiotics and any at home remedies that bring you relief. If you ignore your UTI symptoms the bacteria will likely spread up your urinary tract and may reach your kidneys.

For a simple urinary tract infection, your doctor will likely put you on antibiotics for anywhere from 3-7 days. Your condition should improve within the first couple days of treatment.

Make sure you take the full course of antibiotics to eliminate the infection and to make sure that your UTI is completely cured. Your doctor may also pair the antibiotics for urinary tract infection with bladder anesthetic medication to relieve painful, burning urination.

  • Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  • See a doctor, get treatment and a prescription at your local pharmacy.

  • Use your health insurance just like you normally would to see your doctor.


During your UTI treatment, you can take steps to ensure that you get the maximum effect out of your antibiotics while promoting your own comfort.

  • Use a heating pad on your abdomen to soothe any pain and discomfort and relieve pressure.
  • Drink plenty of water to help flush out the bacteria in your urinary tract.
  • Avoid any food and drink that may irritate your urinary system. This includes coffee, alcohol, and sugary sodas that contain citrus juice or caffeine.

When Does a UTI Turn into a Kidney Infection?

What happens if a UTI goes untreated? If left untreated, the E. coli or other bacteria that caused your urinary tract infection can move farther up your urinary system.

When they reach your upper urinary system (comprising the ureters and kidneys), you may experience a kidney infection, medically known as pyelonephritis.

Most people seek medical help and receive treatment before they get to this point.

Most often, the bacteria involved in a kidney infection are the same that caused the initial bladder or urethral infection. In rare instances, bacteria from your skin or the environment can cause a kidney infection.

Any condition that reduces or obstructs urine flow increases your risk of contracting a kidney infection as it allows bacteria to more easily flow from the bladder, up the ureters, to the kidneys. These conditions include:

Different Types of Kidney Infections

You can generally classify kidney infections into 3 categories:

Uncomplicated infections are simply those that start as urinary tract infections and spread, causing plenty of pain and discomfort but no long-term damage.

A complicated kidney infection is an infection accompanied by a condition that increases the potential for that infection to become severe and for treatments to become ineffective. This includes obstructions or abnormalities in the urinary system or disorders like diabetes. Complicated pyelonephritis also indicates more severe issues related to the kidneys. This includes the formation of abscesses or obstructions in the kidneys or even enlarged kidneys. Complicated kidney infections come with more severe symptoms and are often less responsive to treatments.

Chronic kidney infections are rare and often caused by birth defects, structural abnormalities, or other preexisting issues. Frequent kidney infections can cause scarring and progressive damage to the kidneys. Thankfully, most cases of chronic pyelonephritis are discovered early in childhood. Most cases of kidney infection are cured with traditional treatments and medications, with little lasting damage to the kidneys or urinary system. Most people won’t develop a kidney infection again.


Diagnosing Kidney Infections

Diagnosing a kidney infection involves a variety of tests and examinations. Common tests used include:

  • Urinalysis: In cases of kidney infection, microscopic analysis of urine shows the presence of excess white blood cells, bacteria, and other obvious signs of infection.
  • Urine cultures: Infected urine will grow bacteria within days of being placed on a culture.
  • Kidney ultrasounds: Using a special probe, doctors can direct high-frequency sound waves into the skin to create images of the ureters of the kidneys to help identify any stones, abscesses, or blockages.
  • Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  • See a doctor, get treatment and a prescription at your local pharmacy.

  • Use your health insurance just like you normally would to see your doctor.


Treatments for Urinary and Kidney Infections

Kidney infections always require antibiotics. Don’t rely on home remedies alone to take care of kidney infections.

Usually, doctors will prescribe empiric antibiotics to cover all the potential bacteria that could have caused the infection until they can target the specific bacteria based on test results. Antibiotics are usually prescribed for at least a full week.

Normally, you won’t require a stay at a hospital for a kidney infection as long as you can move around and consistently keep down oral antibiotics.

However, if you exhibit severe symptoms or cannot keep down the medication due to nausea and vomiting, you may be hospitalized so that your doctor may administer antibiotics and fluids intravenously.

If the kidney infection progresses enough to create an abscess in the kidney, you may require more serious treatment. Abscesses cannot be cured with antibiotics alone. In order to drain them, doctors will perform a nephrostomy, which involves placing a tube through your back, into the kidney.

Read: Get Kidney Infection Treatment Online

Preventing Urinary Tract Infections and Kidney Infections

Urinary tract infections and kidney infections can generally be prevented through similar means.

  • Proper hygiene. The best way to ensure you never have to deal with an infection is good hygiene. Washing your genitals and wiping front to back keeps bacteria from potentially entering your urethra.
  • Pee when you need to. Don’t hold it, and try to completely empty your bladder without rushing anything.
  • Urinate soon after sex, and make sure you practice safe sex in general.
  • Diaphragms, unlubricated condoms, and spermicidal lubes can potentially contribute to infection. Diaphragms can prevent proper and complete emptying of the bladder. Consider switching to different birth control methods.
  • For postmenopausal women, certain hormonal therapies, particularly daily application of a topical estriol cream, may help to prevent UTIs and kidney infections.
  • Cranberry juice tends to be the go-to drink to prevent urinary tract and kidney infections. There is conflicting data from both sides, but ultimately, if drinking cranberry juice provides you comfort and seems to help, then feel free to drink it. Just be careful of the extra calories, and avoid drinking it if you take any blood-thinning medication.
  • Women with chronic urinary tract infections may find it helpful to take preventive antibiotic therapy. You can talk to a doctor about it here.
  • Catheters can also lead to urinary tract infections. Individuals with indwelling bladder catheters should remember to have their catheters changed regularly to avoid irritation and infection. Make sure to clean and monitor the area surrounding where the catheter enters the urethra.

If you suffer from any symptoms of a urinary tract or kidney infection, talk to your doctor immediately. The faster you act, the more effective the treatment.

If you experience any symptoms of urinary tract infection or kidney infection, call or book online with PlushCare to set up a phone or video appointment with a top U.S. doctor today.

Read more of our UTI series:


PlushCare is dedicated to providing you with accurate and trustworthy health information.

Mayo Clinic. Urinary Tract Infection (UTI). Accessed September 20, 2019 at https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447

Urology Care Foundation. What is a Urinary Tract Infection (UTI) in Adults?. Accessed September 20, 2019 at https://www.urologyhealth.org/urologic-conditions/urinary-tract-infections-in-adults

Medline Plus. Urinary Tract Infections. Accessed September 20, 2019 at https://medlineplus.gov/urinarytractinfections.html

Mayo Clinic. Kidney Infection. Accessed September 20, 2019 at https://www.mayoclinic.org/diseases-conditions/kidney-infection/symptoms-causes/syc-20353387

American Kidney Fund. Kidney Infection. Accessed September 20, 2019 at http://www.kidneyfund.org/kidney-disease/kidney-problems/kidney-infection.html

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