Kidney Infections vs Bladder Infections

General Health and Preventive Care  /  Blog

Kidney Infections vs Bladder Infections

Sara Menges

Written by Sara Menges

Sara Menges

Sara Menges

Sara enjoys research, art, and seeking a sustainably fun life, balancing physical and mental health.

September 10, 2021 / Read Time 6 minutes

What is the Difference Between a Bladder Infection and a Kidney Infection?

Kidney and bladder infections are both considered urinary tract infections. Although they share similar symptoms, there are differences between the two. A kidney infection’s signs and symptoms vary significantly from person to person and normally develop within a day or as fast as a few hours.

Understanding the difference between a bladder and kidney infection can ensure you take the proper steps towards healing and speeding up doctor consultation sessions.

  1. 1

    Book on our free mobile app or website.

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

  2. 2

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

  3. 3

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

What is a Urinary Tract Infection?

A urinary tract infection (UTI) occurs anywhere in the urinary tract system, which is made up of several different organs. To understand what a urinary tract infection is, we must first understand the urinary tract and the organs that comprise it.

The urinary tract organs are meant to extract, hold, and transport waste from your system in the form of urine. They 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 you feel the need to pee. The body involuntarily contracts the muscles that line the bladder to urinate.

  • The urethra: This tube connects the bladder to the outside of the body. When you pee, a muscle called the urinary sphincter relaxes as your bladder contracts to remove urine from your body.

The urethra and bladder make up the lower urinary tract, and the ureters and kidneys the upper urinary tract. A bacterial infection in any of these four areas is considered a UTI. This includes both bladder and kidney infections. 

Types of Urinary Tract Conditions

A urinary tract infection (UTI) refers to an infection in any area of the urinary tract. Conditions that can occur in the urinary tract or with the potential to lead to complicated infections include:

  • Urethritis: An inflammation of the urethra, usually caused by an infection; for example, a sexually transmitted disease such as chlamydia

  • Cystitis: An infection in the bladder that has often moved up from the urethra, also one of the most common UTIs

  • Nephritis: Any type of kidney inflammation

  • Pyelonephritis: An infection in one or both kidneys

Bladder Infection vs Kidney Infection

The main difference between a bladder infection and a kidney infection is when bacteria have built up and infected the urinary tract system. Although most kidney infections result from untreated bladder infections that migrate to the kidneys, a kidney infection can occur in other ways.

Overall, bladder infections are more common than kidney infections and considered less complicated, especially since kidney infections can lead to serious illness if infections spread through the bloodstream.

A critical difference between bladder infection and kidney infection symptoms is the increased likelihood of illness associated with the infection migrating to the kidneys. The signs and symptoms of a bladder infection that can remain the same even after the infection spreads to the kidneys include:

  • A fever remaining under 101 degrees Fahrenheit

  • Pain and pressure in the pelvis

  • Painful or burning urination

  • Dark and cloudy urine that may appear red from blood

  • Bad-smelling urine

  • Pain in the abdomen

Additional signs and symptoms that indicate an infection has spread to the kidneys include nausea, vomiting, chills, shaking, a fever exceeding 101 degrees Fahrenheit, and, particularly in the elderly, confusion.

What Are The Common Causes Of Urinary Tract Infection?

Treatment for kidney infections can vary depending on the cause and severity of an infection. Infections in the urinary tract most commonly occur when bacteria travel through the urethra to the bladder to use urine as food for growth and multiplication. Excess levels of bacteria can lead to infections that, when they migrate to the kidneys, are known as kidney infections.

The most common cause of an infection in the urinary tract is from the bacteria Escherichia coli, also commonly referred to as E.coli. They are found in our colon and feces. 

Improper wiping or toilet backsplash that accidentally causes the bacteria from the anus to contact the genitals is one of the most common ways to spread E. coli into the urinary tract. Bacteria transfer can also occur during sex; irritation of the urethra from frequent sexual intercourse can increase women’s likelihood to develop cystitis. Men or women who take part in unprotected anal sex are also more likely to develop urinary tract infections.

Certain sexually transmitted infections, including chlamydia, herpes, gonorrhea, and mycoplasma, can also lead to an infection that spreads to the kidneys. Holding your urine for six hours or more can give time for bacteria that enter the bladder to overgrow without being flushed out, increasing the risk of infection.

Dehydration can also increase the risk of infection. Without the proper fluids, your body can not properly flush out bacteria that can cause urinary tract infections (UTIs). Constipation, a possible result of dehydration, can make it difficult to empty your bladder and allow trapped bacteria to grow as well.

Infections can also be caused by any condition in the urinary tract that prevents urine from flowing naturally. For instance, pregnant women are likely to get bladder infections when the baby puts pressure on the ureters, slowing urine flow. 

Other people at risk due to a condition that prevents proper voiding of urine from the body include those with:

  • Any blockages in the urinary tract caused by conditions like an enlarged prostate or kidney stone

  • Structural or anatomic problems in the urinary tract, such as a stricture urethra

  • Conditions like vesicoureteral reflux (VUR), where urine flows backward toward the kidneys from the bladder

  • Spinal cord injury and other conditions that prevent you from adequately emptying your bladder

For a hassle-free approach to addressing urinary tract infections, consider exploring online UTI treatment options with PlushCare. Through online consultations, your doctor can assess your symptoms and, if appropriate, prescribe a suitable medication to effectively treat the infection.

What Are Other Causes of Kidney Infection?

Although a kidney infection can result from a bladder infection, a kidney infection doesn’t always begin with a bladder infection. Anything that changes the bacterial environment in your urinary tract system can increase the risk of infection, including any inflammation of the area, menopause, or the intake of medications altering the hormones in your body.

People with a weakened immune system are also at increased risk of developing infections. This includes people with malfunctioning bladder, urethra, or ureters, and anyone with a condition that suppresses the immune system, such as HIV/AIDS, diabetes, or chemotherapy.

Although rare, they can develop a kidney infection through their bloodstream due to their immune system’s state. Bacterial or fungal infections on the skin can spread into the blood and end up in the kidney during the blood filtering stage.

  1. 1

    Book on our free mobile app or website.

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

  2. 2

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

  3. 3

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

Preventative Care for Urinary Tract Infections

Whether you are at risk of a bladder or kidney infection, methods reducing the likelihood of bacteria entering the urethra and spreading to the bladder are effective ways to prevent either infection from developing.

The primary way to prevent urinary tract infection is to pee when you need to and trying to empty the bladder. Holding urine can lead to bacteria build-up and irritation in the urinary tract.

Staying hydrated is a critical way to ensure frequent flushing of bacteria from the urinary tract. Drinking lots of fluids can prevent constipation from occurring and other irritating kidney infection symptoms.

Fiber-rich foods such as apples and cabbages are also effective preventative measures for constipation. Staying hydrated can also be done by drinking water or tea and avoiding sugary or caffeinated beverages.

Other home remedies include using a heating pad on your belly, back, or side to soothe pains and aches from infections.

Good hygiene also contributes to preventing further infection. Other methods for reducing the risk of infection include:

  • Urinate soon after sex, and make sure you practice safe sex in general

  • Contraceptive diaphragms prevent proper and complete emptying of the bladder; consider switching to different birth control methods

  • Women with chronic urinary tract infections may find it helpful to take preventive antibiotic therapy

Home remedies can provide symptom relief and prevent recurring infections from occurring. Having said this, a significant infection will require one of the various available antibiotics. Good indicators about when to add a doctor visit to your home remedies for kidney infection include a significant change to your usual urination pattern accompanied by any severe symptoms of an infection.

Generally, kidney infection symptoms will feel worse during urination. When this pain is accompanied by a fever and persistent genital, stomach, or lower back pain, it is more likely to be a kidney infection than a bladder infection.

If you experience any symptoms above, book an appointment online with PlushCare to set up a phone appointment with a top U.S. doctor today.

Read More About Kidney Infections and Bladder Infections


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

Most PlushCare articles are reviewed by M.D.s, Ph.Ds, N.P.s, nutritionists and other healthcare professionals. Click here to learn more and meet some of the professionals behind our blog. The PlushCare blog, or any linked materials are not intended and should not be construed as medical advice, nor is the information a substitute for professional medical expertise or treatment. For more information click here.

Our commitment to you.

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

Research from sources you can trust

Medical reviews by field experts

Frequent content updates