How fast can a kidney infection kill you?

Medically reviewed by Dr. Samra


A kidney infection can potentially lead to life-threatening complications if not treated timely. In severe cases, if left untreated, a kidney infection can result in death within a matter of days. Bacteria, primarily, are responsible for these infections. However, effective treatment is available in the form of antibiotics. It’s crucial to seek medical attention at the onset of symptoms to prevent bacteria or viruses from causing permanent kidney damage. Keep reading to know the early signs of kidney infection and to start your treatment without delay.

Is it possible to die from a kidney infection?

A kidney infection, or pyelonephritis, occurs when harmful bacteria or viruses travel from the urethra to the ureters and into the kidneys. This infection can affect one or both kidneys and presents early symptoms similar to those of a urinary tract infection (UTI). However, if left untreated, a kidney infection can lead to serious kidney damage, disease, and even death. Kidney infections require urgent medical attention due to their potential severity. 
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), kidney infections account for most hospitalizations for urinary tract infections in the United States annually, indicating their seriousness.

Experiencing frequent urination and lower-side pain? Clear your suspicion of kidney infection.

What are the symptoms of a kidney infection?

Symptoms of a kidney infection can vary but often include:

  • Fever
  • Chills
  • Pain in your lower back or side
  • Pain or burning sensation when you urinate
  • Bloody or cloudy urine that might have a foul odor
  • Urgent or frequent need to urinate
  • Feeling that you can’t empty the bladder fully
  • Lower stomach pain

The early symptoms of a kidney infection may overlap with those of a bladder infection, making them challenging to differentiate. Warning signs of an infection can include high fever, pain during urination, frequent urination, blood or pus in the urine, nausea, vomiting, and stomach pain. It’s crucial to seek medical advice from a healthcare provider immediately upon noticing these symptoms.

What causes kidney infections?

Kidneys are crucial in filtering waste and producing urine to eliminate it from your body. The urine travels through tubes called ureters to your bladder, where it’s stored until you urinate. Normally, this process flushes out any bacteria or other germs in your urinary tract.

In case of infection, bacteria can reach one or both of your kidneys from there, leading to a kidney infection. Bacterial infections, especially gram-negative bacteria, are the primary cause of kidney infections. These bacteria are often highly resistant to drugs, including certain antibiotics such as:

  • E. coli
  • Enterobacter
  • Staphylococcus
  • Proteus mirabilis

The most prevalent bacterium associated with kidney infections is Escherichia coli (or E. coli), typically in the bowel. However, it can enter the urinary tract during activities such as sex or inadequate hygiene practices after bowel movements.

Bacteria can enter the kidneys through two main routes: via the bloodstream, often during surgical procedures, or through the urinary tract. While the body can usually flush out bacteria from the urinary tract with urine, sometimes bacteria manage to remain and cause an infection.

Bacteria causing kidney infection can complicate your condition. Get diagnosis and treatment from home.

What are the risk factors for kidney infection?

Risk factors for kidney infections encompass various conditions and situations that can increase the likelihood of developing this serious condition.

  • Urinary tract blockage: Anything that obstructs the normal urine flow out of the urinary tract can create an environment conducive to bacterial growth and increase the risk of kidney infection. This includes conditions such as kidney stones, an enlarged prostate, or uterine prolapse. Additionally, pressure on the bladder during pregnancy can further elevate the risk.
  • Underlying health conditions: Certain health conditions, such as diabetes, HIV, or being on immunosuppressive medications, can weaken the immune system and predispose individuals to infections, including kidney infections.
  • Anatomical factors: Women and individuals without a penis have a shorter urethra, which facilitates easier passage of bacteria from the genitals to the bladder and kidneys, increasing the risk of infection.
  • Other factors: Additional risk factors for kidney infections include catheter use, urinary tract defects, urinary retention, and conditions that weaken the immune system.

What are the differences between UTI and kidney infection?

A kidney infection is a type of urinary tract infection (UTI), but the term “UTI” commonly refers to infections of the lower urinary tract, such as the bladder or urethra. While both conditions can share similar symptoms, a kidney infection typically presents more severe symptoms that can suddenly make you feel unwell, including fever, chills, and pain in the lower back or side.

Symptoms of UTIs include pain or burning during urination, cloudy, bloody, or foul-smelling urine, difficulty urinating, frequent urges to urinate, and lower back pain.

In contrast, a kidney infection can appear with similar symptoms as a UTI, along with additional symptoms such as chills, fever, pain in the back, side, or groin, nausea, and vomiting.

Ultimately, your physician is the best person to determine whether you have a UTI or kidney infection. Discuss any ongoing symptoms during your examination, and may prescribe lab requisitions for further clarity.

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

There is no set timeframe for how quickly a urinary tract infection (UTI) can progress from the bladder to the kidneys. The transition from a UTI to a kidney infection can vary depending on individual factors and the severity of the infection. Treatment for a mild kidney infection typically lasts 7 to 14 days. However, symptoms may take a week or longer to resolve completely with treatment.

How is a kidney infection treated?

Kidney infections are typically treated with antibiotics prescribed by healthcare providers. The duration of antibiotic treatment usually spans at least two weeks. In cases of severe illness or if symptoms persist despite antibiotic therapy, hospitalization or an extended course of antibiotics may be necessary.

The treatment approach for kidney infections depends on the underlying cause. Bacterial infections, which are the most common form of kidney infection, are effectively treated with a course of antibiotic medication. While some severe cases may require hospitalization for intensive treatment, most infections can be managed with oral antibiotics. Commonly prescribed antibiotics for kidney infections include:

Six weeks after treatment, your doctor may order urine tests to confirm the infection has been successfully eradicated.

Get prescription medications for kidney infection. Our doctors will prescribe you the right antibiotic course.

How long does a kidney infection last?

With proper treatment, symptoms of a kidney infection typically begin to improve within a few days. However, it’s essential to complete the course of antibiotics as your healthcare provider prescribes, typically two weeks. 

The recovery process may extend over several weeks for some individuals, particularly those with more difficult-to-treat infections. It’s important to follow your doctor’s recommendations closely and attend any follow-up appointments to ensure the infection has been successfully treated.

What are the complications of kidney infection?

Kidney infections, if left untreated, can escalate into severe and potentially life-threatening complications, particularly in individuals with compromised immune systems or underlying health conditions. These complications may include:

  • Emphysematous pyelonephritis: This condition involves the destruction of kidney tissue by bacteria, leading to gas formation within the kidney. It is more prevalent in individuals with diabetes.
  • Renal papillary necrosis: This condition causes kidney damage and can significantly impair kidney function.
  • Sepsis and potential death: Untreated kidney infections can progress to sepsis, a severe and potentially life-threatening condition characterized by a systemic inflammatory response to infection.
  • Renal abscess formation: Pus-filled abscesses may develop within the kidneys, posing a risk of further infection and tissue damage.
  • Hypertension (high blood pressure): Kidney infections can contribute to developing high blood pressure, which, if left uncontrolled, can increase the risk of cardiovascular complications.
  • Kidney scarring: Chronic or recurrent kidney infections may lead to scarring of the kidney tissue, impairing its function over time.
  • Chronic kidney disease and kidney failure: Persistent kidney infections can result in chronic kidney disease (CKD) or kidney failure, where the kidneys lose their ability to function properly.

It’s crucial to seek medical attention upon noticing kidney infection symptoms to prevent complications. If sepsis symptoms such as high fever or low body temperature, severe breathlessness, rapid heartbeat, altered mental state, muscle pain, nausea, vomiting, diarrhea, dizziness, or fainting occur, urgent medical care should be sought as sepsis can be life-threatening.

How are kidney infections diagnosed?

Diagnosing a kidney infection involves a comprehensive assessment of symptoms and various diagnostic tests by healthcare providers. The diagnostic process typically includes the following steps:

  • Clinical assessment: Healthcare providers review your medical history, inquire about symptoms, and conduct a physical examination to evaluate signs of a kidney infection.
  • Urine Testing (urinalysis): Urinalysis is a primary diagnostic tool used to detect signs of infection in the urine, such as bacteria and white blood cells. Additionally, urinalysis may assess chemical balances in the urine, including acidity, protein levels, glucose, ketones, nitrates, white blood cells, bilirubin, and blood. Abnormal levels of these substances can indicate underlying kidney or urinary tract disorders.
  • Imaging Tests: Imaging tests such as CT scans or renal ultrasounds may be ordered to visualize the kidneys and identify abnormalities, such as blockages or collections. These tests provide valuable insights for healthcare providers to tailor treatment plans and prevent potential complications.

Timely diagnosis and treatment of kidney infections are crucial to prevent potential complications, including life-threatening conditions. If you experience symptoms suggestive of a kidney infection, seeking medical attention is essential for timely diagnosis and appropriate management.

Drink plenty of water to reduce the risk of kidney infections. Get personalized advice on managing your condition.

How to prevent kidney infection?

Preventing kidney infections often begins with minimizing the risk of lower urinary tract infections, which can progress to more severe kidney infections. Here are some essential steps to prevent infections in all parts of the urinary tract:

  • Hydration: Drink plenty of fluids, particularly water, to promote frequent urination and flush bacteria out of the urinary tract. 
  • Bladder emptying: Ensure you fully empty your bladder regularly. Holding in urine can facilitate bacterial growth, increasing the risk of infection.
  • Urination habits: Urinate before and after sexual intercourse to help eliminate bacteria from the urinary tract. Immediate urination when feeling the urge can also prevent bacterial buildup.
  • Hygiene practices: Maintain good hygiene practices, including regular showering and changing out of wet or sweaty underwear to minimize bacterial growth. Wipe from front to back to avoid the risk of bacteria traveling up to the urethra.

Incorporating these preventive measures into your daily routine can significantly reduce the risk of developing a kidney infection.

When should I see a doctor?

It’s essential to consult a healthcare provider if you experience difficulty urinating or observe any changes in your urine, such as blood or cloudiness. These symptoms may indicate underlying urinary tract issues, including a potential kidney infection, and warrant medical evaluation.

Signs that require urgent evaluation include:

  • Sudden onset of fever or pain
  • Confusion or mental changes
  • Severe shortness of breath
  • Decreased urination

If you experience any symptoms suggestive of a severe kidney infection or related complications, do not hesitate to seek immediate medical care at the nearest emergency room.

FAQs about kidney infection

How fast can a kidney infection turn into sepsis?

Sepsis can develop rapidly from an initial kidney infection and progress to septic shock in as little as 12 to 24 hours. If you have an infection that’s not improving or experiencing symptoms of illness, seeking medical attention is essential.

How fatal can a kidney infection be?

A severe kidney infection poses serious risks, including blood poisoning, tissue damage, or, in extreme cases, mortality. If symptoms such as bloody urine, nausea, vomiting, or other concerning signs occur, consult a medical professional.

When does a kidney infection become an emergency?

Emergency medical care is warranted if you experience severe pain that typically manifests as persistent, intense flank discomfort often accompanied by systemic symptoms such as fever and nausea, Difficulty maintaining hydration levels.

What is the pain level of a kidney infection?

Pain linked to a kidney infection is typically described as a dull, aching sensation primarily felt in the back, side, or abdomen. Additional symptoms may include changes in urine color, odor, or the presence of blood.

Your Doctors Online uses high-quality and trustworthy sources to ensure content accuracy and reliability. We rely on peer-reviewed studies, academic research institutions and medical associations to provide up-to-date and evidence-based information to the users.

  • Kunin, Calvin M. “Does kidney infection cause renal failure?.” Annual review of medicine 36.1 (1985): 165-176.
  • Prasad, Narayan, and Manas Ranjan Patel. “Infection-induced kidney diseases.” Frontiers in medicine 5 (2018): 327.
  • Naqvi, Sakina B., and Allan J. Collins. “Infectious complications in chronic kidney disease.” Advances in chronic kidney disease 13.3 (2006): 199-204.
  • Dalrymple, Lorien S., et al. “The risk of infection-related hospitalization with decreased kidney function.” American journal of kidney diseases 59.3 (2012): 356-363.
  • Syed-Ahmed, Maaz, and Mohanram Narayanan. “Immune dysfunction and risk of infection in chronic kidney disease.” Advances in chronic kidney disease 26.1 (2019): 8-15.

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