How Long Does It Take for a UTI to Turn into a Kidney Infection: Understanding the Progression

Monali Sharma
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Dr. Kaushal

Review medical content on WOW Rx Pharmacy, so that accurate drug use information is easily accessible to everybody.
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how long does it take for a uti to turn into a kidney infection

Most Urinary Tract Infections (UTIs) are typically mild and treatable with a course of antibiotics.

However, there is a potential risk of them advancing to a more severe kidney infection, Pyelonephritis.

We will explore the timeline and crucial factors behind UTI kidney infection and ways to prevent it.

There is no one-size-fits-all answer to how long does it take for a UTI to turn into a kidney infection.

To understand the pace of UTI kidney infection, let’s first understand the physiology behind UTIs and kidney infections.

Understanding UTIs and kidney infection

Urinary Tract Infections are primarily caused by bacteria, particularly Escherichia coli (E. coli), entering the urinary tract through the urethra.

Bacteria from the perineal skin, located between the rectum and genitals, enter the urethra and subsequently migrate into the bladder.

While UTIs are more prevalent in women due to their shorter urethra, they can also affect men and children.

If left unnoticed or untreated, a bladder infection can extend its spread upwards through the ureters and ultimately reach the kidneys, known as upper UTI or Pyelonephritis.

UTI kidney infection may also result from a low response to the antibiotics in an individual, which lets the bacteria grow at a higher rate.

UTI kidney infection affects approximately 15 to 17 out of every 10,000 females and 3 to 4 out of every 10,000 males annually in the United States.

A surgical procedure can serve as another cause of a kidney infection, as bacteria can enter the body during the operation and travel to the kidneys via the bloodstream.

How long does it take for a UTI to turn into a kidney infection

Most UTIs primarily affect the lower urinary tract, including the urethra and bladder.

But in some cases, infection may advance to the upper urinary tract, affecting one or both kidneys.

There is no specific timeframe or rule regarding the duration of a UTI to turn into a kidney infection.

The progression of UTI kidney infection is influenced by several factors, including the severity of the condition and the immunity strength of the individual.

In some cases, a UTI has the potential to rapidly transform into a UTI kidney infection in just a few days.

Recognizing the signs of kidney infection

Painful and frequent urinationSource: Prostock-studio
Painful urination

The typical symptoms one experiences during UTIs include:

  • Painful, frequent urination
  • Urgent need for urinal discharge
  • Dark, cloudy, or foul-smelling urine
  • Sometimes blood in the urine

However, a few signs can indicate that the infection has advanced to the kidneys.

In UTI kidney infection, you may encounter additional or elevated symptoms beyond those mentioned previously.

Typically, symptoms will manifest within a few hours or may gradually appear over the span of a day.

These can include:

  • Chills
  • Fever
  • Pain in your back, side, or groin
  • Nausea
  • Vomiting
  • Weakness or fatigue
  • Increased frequency and urgency of urination.

If you notice these signs, UTI has probably advanced to your kidneys.

It is crucial to inform your doctor and receive appropriate treatment immediately.

A timely diagnosis and treatment can help combat UTI kidney infection and make you feel better. 

Diagnosing and treating UTI turned into kidney infection

urine test and urine culture are medical methodsSource: pixelshot
Urine test

Diagnosing a UTI kidney infection involves an examination of your symptoms and medical history.

In addition to the initial signs of the UTI kidney infection, a urine test and a urine culture are medical methods to confirm the diagnosis.

A urine test is done to check for blood, pus, and bacteria in your pee, and a urine culture tells what kind of bacteria you have.

The treatment approach to UTI kidney infection involves the administration of antibiotics to eliminate the bacteria.

You may also need medication to alleviate the fever, and flank pain.

Timely identification and administration of antibiotics can contribute to a full recovery within approximately two weeks.

Completing the entire course of antibiotics is crucial, even if symptoms improve.

Discontinuing the medication prematurely could lead to bacterial growth and a recurrence of the infection.

If your infection has reached a severe stage, hospitalization may be necessary, and you may receive intravenous (IV) antibiotics administered through a needle.

Failure to treat a kidney infection can lead to a worsening of the condition and, in some cases, result in lasting damage to the kidneys.


A UTI is a bacterial infection in the urinary tract of the body. 

If a UTI goes unnoticed or untreated, it can progress upward through the ureters and eventually reach the kidneys, known as Pyelonephritis.

The time in which a UTI turns into a kidney infection differs with each individual.

It depends upon the severity of the infection and the individual’s response to the treatment. 

If you experience fever and chills, flank pain, nausea, and vomiting, it’s possible that the infection has ascended to your kidneys.

It is important to promptly approach a medical expert and receive treatment as the UTI kidney infection has the potential to grow into a very serious condition.  

A course of antibiotics is the standard approach to treat UTI kidney infection.

Your doctor may need to examine your urine to decide the suitable antibiotic and dosage for you.

Frequently Asked Questions

How do you know if a UTI has gone to your kidneys?

Besides the common UTI symptoms like painful and frequent urination, cloudy or bloody urine, and pelvic discomfort, additional symptoms such as fever, chills, back or side pain, nausea, and vomiting may suggest that the UTI has progressed to the kidneys. A urine test will further confirm the infection in the kidneys.

How long does it take for a UTI to spread to kidneys?

The duration for a UTI to progress into a kidney infection does not follow a specific timeframe or rule. The severity of the condition and the effectiveness of the treatment influences the progression of a UTI kidney infection. Sometimes, a UTI can quickly develop into a kidney infection within a few days.

What are the 3 early signs of kidney disease?

Three early signs of kidney disease are improper urination in occurrence and appearance, fatigue and weakness because of toxins buildup, pain in your back and side, and nausea and vomiting.

What does it feel like when a UTI turns into a kidney infection?

Symptoms such as fever, chills, nausea, and vomiting are commonly experienced when a kidney infection occurs. These heightened symptoms can create a sense of overall illness in an individual and contribute to increased fatigue and feelings of tiredness.

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