Table of ContentsView AllTable of ContentsCausesSymptomsComplicationsIs Hospitalization Needed?DiagnosisTreatmentPrognosis
Table of ContentsView All
View All
Table of Contents
Causes
Symptoms
Complications
Is Hospitalization Needed?
Diagnosis
Treatment
Prognosis
There are times when the symptoms of akidney infectioncan turn severe. Knowing the signs and when to go to the hospital can help you avoid potentially life-threatening complications likekidney failureandsepsis.
A kidney infection (also known aspyelonephritis) is a type ofurinary tract infection (UTI)that typically starts in the tube that carries urine from the body (urethra) or thebladder. While many cases can be treated at home with oral antibiotics, hospitalization may be needed for especially severe cases.
This article explains how kidney infections occur, including the causes and symptoms. It also describes the signs of a severe kidney infection and what to expect if hospitalization is needed.
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How Does a Kidney Infection Start?
Most cases start off as alower urinary tract infectionthat migrates up the urethra to the bladder. Thereafter, the infection can spread to one or both kidneys through tubes that connect the bladder to the kidneys, calledureters.
On rare occasions, a kidney infection can occur after kidney surgery or when an infection from another surgery (such as a heart valve or artificial joint replacement) spreads to the kidneys.
Kidney infections affect females more than males due to their urethras being shorter and situated close to the anus. Fluctuations in the hormoneestrogen—which helps maintain the integrity of vaginal and urinary tract tissues—can also increase the risk of infection during menstruation, pregnancy, and menopause.
Several other factors can significantly increase your risk of a kidney infection, including:
Causes of Kidney Pain You Should Know
What Does a Kidney Infection Feel Like?
A kidney infection can either beacute(sudden and severe) orchronic(persistent or recurrent). Both can cause serious complications if left untreated.
Acute pyelonephritistypically develops quickly over the course of a few hours or a day, causing symptoms like:
When to Go to the Hospital for a Kidney Infection
How Severe Is a Kidney Infection?
Acute pyelonephritis is designated as either uncomplicated or complicated. Uncomplicated kidney infections can usually be treated at home, while complicated cases may requireinpatient carein a hospital.
Complicated acute pyelonephritis most often affects vulnerable people, includingimmunocompromisedpeople, pregnant people, and people with uncontrolled diabetes,kidney transplants, urinary tract abnormalities, and hospital-acquired bacterial infections.
Complications of acute pyelonephritis include:
When to Make an Office Appointment
Any time you havesymptoms of a urinary tract infection, contact a healthcare provider. They will likely order a urine test and schedule an office visit or direct you to an urgent care clinic.
Common symptoms of a UTI include:
When to Go to the Hospital
Although many lower UTIs will clear on their own, upper UTIs like pyelonephritis are less likely to do so and may turn serious quickly.
Given that acute pyelonephritis develops rapidly, it is important to seek immediate care if you develop symptoms. If your healthcare provider is unavailable, go to your nearest urgent care center. When treated early, most kidney infections can be cleared with a short course of antibiotics.
In other instances, you will need to call 911 or go to the emergency room—especially if there are signs of acute renal failure or sepsis. If left untreated, sepsis can lead toseptic shock, causing organ failure and death, sometimes within 12 hours.
Signs of a medical emergency include:
Do You Have to Be Hospitalized to Treat a Kidney Infection?
Certain people with pyelonephritis may need to be hospitalized even if their symptoms do not seem critical. This is because the risk of complications is high.
Hospitalization may be needed if you have a severe kidney infection and you:
Acute Pyelonephritis and PregnancyPyelonephritis affects approximately 2% of all pregnancies in the United States, with 80% to 90% of cases occurring during the second and third trimesters. It is associated with a high risk of complications (including maternal sepsis andpreterm birth) as well as an increased risk of maternal and fetal death.
Acute Pyelonephritis and Pregnancy
Pyelonephritis affects approximately 2% of all pregnancies in the United States, with 80% to 90% of cases occurring during the second and third trimesters. It is associated with a high risk of complications (including maternal sepsis andpreterm birth) as well as an increased risk of maternal and fetal death.
How Is a Kidney Infection Diagnosed?
A kidney infection is mainly diagnosed with urine tests and imaging studies. The results of the tests will help direct the appropriate treatment.
These include:
Differential Diagnosis
As part of the diagnosis, your healthcare provider may want to exclude other conditions that mimic the signs of a kidney infection. This helps ensure the correct treatment is given.
Among the conditions commonly included in thedifferential diagnosisare:
What Is the Treatment for Kidney Infection Like?
When hospitalization is needed, the treatment is more oftenintravenous(IV; delivered into a vein). This is because:
In some cases, IV antibiotics are combined with oral antibiotics.
The choice of IV antibiotic depends on how severe the infection is and whether the bacteria are resistant to a group of antibiotics known as beta-lactams (which includepenicillins).
The standard duration of therapy is seven to 14 days.
Intravenous Antibiotic Treatment for a Kidney InfectionMild to Moderate InfectionCefepime 1–2 g once dailyCeftriaxone 1 g once dailyCipro (ciprofloxacin) 400 mg every 12 hoursGaramycin (gentamicin) 5 mg/kg once dailyLevofloxacin, 750 mg once dailyZosyn (piperacillin + tazobactam) 3.375–4.5 g every 6 hoursSevere or Beta-Lactam ResistanceAvycaz (ceftazidime + avibactam) 2.5 g every 8 hoursInvanz (ertapenem) 1 g once dailyMerrem (meropenem) 1 g every 8 hoursPrimaxin (imipenem +cilastatin) 500 mg every 6 hoursVabomere (meropenem + vaborbactamZemdri (plazomicin) 15 mg/kg once dailyZerbaxa (ceftolozane +tazobactam) 1.5 g every 8 hours
Intravenous Antibiotic Treatment for a Kidney Infection
Mild to Moderate InfectionCefepime 1–2 g once dailyCeftriaxone 1 g once dailyCipro (ciprofloxacin) 400 mg every 12 hoursGaramycin (gentamicin) 5 mg/kg once dailyLevofloxacin, 750 mg once dailyZosyn (piperacillin + tazobactam) 3.375–4.5 g every 6 hours
Cefepime 1–2 g once daily
Ceftriaxone 1 g once daily
Cipro (ciprofloxacin) 400 mg every 12 hours
Garamycin (gentamicin) 5 mg/kg once daily
Levofloxacin, 750 mg once daily
Zosyn (piperacillin + tazobactam) 3.375–4.5 g every 6 hours
Severe or Beta-Lactam ResistanceAvycaz (ceftazidime + avibactam) 2.5 g every 8 hoursInvanz (ertapenem) 1 g once dailyMerrem (meropenem) 1 g every 8 hoursPrimaxin (imipenem +cilastatin) 500 mg every 6 hoursVabomere (meropenem + vaborbactamZemdri (plazomicin) 15 mg/kg once dailyZerbaxa (ceftolozane +tazobactam) 1.5 g every 8 hours
Avycaz (ceftazidime + avibactam) 2.5 g every 8 hours
Invanz (ertapenem) 1 g once daily
Merrem (meropenem) 1 g every 8 hours
Primaxin (imipenem +cilastatin) 500 mg every 6 hours
Vabomere (meropenem + vaborbactam
Zemdri (plazomicin) 15 mg/kg once daily
Zerbaxa (ceftolozane +tazobactam) 1.5 g every 8 hours
How a Kidney Infection Is Treated
What Is My Outlook After a Kidney Infection?
The prognosis for a kidney infection is generally good if the appropriate treatment is delivered in a timely manner. This is true even if a person develops acute kidney failure, the condition of which is usually reversible.
The same cannot be said if treatment is delayed. In some cases, a kidney infection can severely damage the kidneys, leading to lifelongchronic kidney disease (CKD).
With emphysemic pyelonephritis (one of the most severe complications of acute pyelonephritis). the risk of death is high if left untreated. If treated appropriately, nearly 9 out of 10 people recover, albeit with some level of kidney dysfunction.
For people with complicated acute pyelonephritis, the risk of death from sepsis andseptic shockis as high as 17.7% (or roughly 1 out of 6 people).
Summary
Complicated acute pyelonephritis may require hospitalization, particularly in older people, immunocompromised people, pregnant people, or those with medical conditions like diabetes, multiple sclerosis, or cancer.
Unlike ordinary urinary tract infections (UTIs), kidney infections rarely resolve on their own. For hospitalized people, the treatment usually involves IV fluids and antibiotics. The choice of antibiotics varies based on the severity of the infection and the absence or presence of antibiotic-resistant bacteria.
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Keenan DB, O’Rourke DM, Courtney AE.Pyelonephritis can lead to life-threatening complications.Practitioner. 2017;261(1801):17-20.Herness J, Buttolph A, Hammer NC.Acute pyelonephritis in adults: rapid evidence review.Am Fam Physician.2020;102(3):173-180.McKertich K, Hanegbi U.Recurrent UTIs and cystitis symptoms in women.Aust J Gen Pract. 2021;50(4):199-205. doi:10.31128/AJGP-11-20-5728MedlinePlus.Urinary tract infections - adults.Fogo AB, Lusco MA,Najafian B, Alpers CE.AJKD atlas of renal pathology: chronic pyelonephritis.Atlas Renal Pathol.2016;68(4):E23-5. doi:10.1053/j.ajkd.2016.08.001Ruiz-Mesa JD, Marquez-Gomez I, Sena G, et al.Factors associated with severe sepsis or septic shock in complicated pyelonephritis.Medicine (Baltimore),2017;96(43):e8371. doi:10.1097/MD.0000000000008371Moraes RB, Serafina TF, Vidart J, et al.Time to clearance of abdominal septic focus and mortality in patients with sepsis.Rev Bras Ter Intensiva.2020;32(2):245–250. doi:10.5935/0103-507X.20200029Khoo KSM, Lim ZY, Chai CY, Mahadevan M, Kuan WS.Management of acute pyelonephritis in the emergency department observation unit.Singapore Med J.2021;62(6):287–295. doi:10.11622/smedj.2020020National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of kidney infection (pyelonephritis).American College of Physicians.ACP’s best practice advice addresses appropriate use of short course antibiotics in common infections.Misgar RA, Mubarik I, Wani AI, Bashir MI, Ramzan M, Laway BA.Emphysematous pyelonephritis: a 10-year experience with 26 cases.Indian J Endocrinol Metab.2016;20(4):475–480. doi:10.4103/2230-8210.183475
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Keenan DB, O’Rourke DM, Courtney AE.Pyelonephritis can lead to life-threatening complications.Practitioner. 2017;261(1801):17-20.Herness J, Buttolph A, Hammer NC.Acute pyelonephritis in adults: rapid evidence review.Am Fam Physician.2020;102(3):173-180.McKertich K, Hanegbi U.Recurrent UTIs and cystitis symptoms in women.Aust J Gen Pract. 2021;50(4):199-205. doi:10.31128/AJGP-11-20-5728MedlinePlus.Urinary tract infections - adults.Fogo AB, Lusco MA,Najafian B, Alpers CE.AJKD atlas of renal pathology: chronic pyelonephritis.Atlas Renal Pathol.2016;68(4):E23-5. doi:10.1053/j.ajkd.2016.08.001Ruiz-Mesa JD, Marquez-Gomez I, Sena G, et al.Factors associated with severe sepsis or septic shock in complicated pyelonephritis.Medicine (Baltimore),2017;96(43):e8371. doi:10.1097/MD.0000000000008371Moraes RB, Serafina TF, Vidart J, et al.Time to clearance of abdominal septic focus and mortality in patients with sepsis.Rev Bras Ter Intensiva.2020;32(2):245–250. doi:10.5935/0103-507X.20200029Khoo KSM, Lim ZY, Chai CY, Mahadevan M, Kuan WS.Management of acute pyelonephritis in the emergency department observation unit.Singapore Med J.2021;62(6):287–295. doi:10.11622/smedj.2020020National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of kidney infection (pyelonephritis).American College of Physicians.ACP’s best practice advice addresses appropriate use of short course antibiotics in common infections.Misgar RA, Mubarik I, Wani AI, Bashir MI, Ramzan M, Laway BA.Emphysematous pyelonephritis: a 10-year experience with 26 cases.Indian J Endocrinol Metab.2016;20(4):475–480. doi:10.4103/2230-8210.183475
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Keenan DB, O’Rourke DM, Courtney AE.Pyelonephritis can lead to life-threatening complications.Practitioner. 2017;261(1801):17-20.Herness J, Buttolph A, Hammer NC.Acute pyelonephritis in adults: rapid evidence review.Am Fam Physician.2020;102(3):173-180.McKertich K, Hanegbi U.Recurrent UTIs and cystitis symptoms in women.Aust J Gen Pract. 2021;50(4):199-205. doi:10.31128/AJGP-11-20-5728MedlinePlus.Urinary tract infections - adults.Fogo AB, Lusco MA,Najafian B, Alpers CE.AJKD atlas of renal pathology: chronic pyelonephritis.Atlas Renal Pathol.2016;68(4):E23-5. doi:10.1053/j.ajkd.2016.08.001Ruiz-Mesa JD, Marquez-Gomez I, Sena G, et al.Factors associated with severe sepsis or septic shock in complicated pyelonephritis.Medicine (Baltimore),2017;96(43):e8371. doi:10.1097/MD.0000000000008371Moraes RB, Serafina TF, Vidart J, et al.Time to clearance of abdominal septic focus and mortality in patients with sepsis.Rev Bras Ter Intensiva.2020;32(2):245–250. doi:10.5935/0103-507X.20200029Khoo KSM, Lim ZY, Chai CY, Mahadevan M, Kuan WS.Management of acute pyelonephritis in the emergency department observation unit.Singapore Med J.2021;62(6):287–295. doi:10.11622/smedj.2020020National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of kidney infection (pyelonephritis).American College of Physicians.ACP’s best practice advice addresses appropriate use of short course antibiotics in common infections.Misgar RA, Mubarik I, Wani AI, Bashir MI, Ramzan M, Laway BA.Emphysematous pyelonephritis: a 10-year experience with 26 cases.Indian J Endocrinol Metab.2016;20(4):475–480. doi:10.4103/2230-8210.183475
Keenan DB, O’Rourke DM, Courtney AE.Pyelonephritis can lead to life-threatening complications.Practitioner. 2017;261(1801):17-20.
Herness J, Buttolph A, Hammer NC.Acute pyelonephritis in adults: rapid evidence review.Am Fam Physician.2020;102(3):173-180.
McKertich K, Hanegbi U.Recurrent UTIs and cystitis symptoms in women.Aust J Gen Pract. 2021;50(4):199-205. doi:10.31128/AJGP-11-20-5728
MedlinePlus.Urinary tract infections - adults.
Fogo AB, Lusco MA,Najafian B, Alpers CE.AJKD atlas of renal pathology: chronic pyelonephritis.Atlas Renal Pathol.2016;68(4):E23-5. doi:10.1053/j.ajkd.2016.08.001
Ruiz-Mesa JD, Marquez-Gomez I, Sena G, et al.Factors associated with severe sepsis or septic shock in complicated pyelonephritis.Medicine (Baltimore),2017;96(43):e8371. doi:10.1097/MD.0000000000008371
Moraes RB, Serafina TF, Vidart J, et al.Time to clearance of abdominal septic focus and mortality in patients with sepsis.Rev Bras Ter Intensiva.2020;32(2):245–250. doi:10.5935/0103-507X.20200029
Khoo KSM, Lim ZY, Chai CY, Mahadevan M, Kuan WS.Management of acute pyelonephritis in the emergency department observation unit.Singapore Med J.2021;62(6):287–295. doi:10.11622/smedj.2020020
National Institute of Diabetes and Digestive and Kidney Diseases.Diagnosis of kidney infection (pyelonephritis).
American College of Physicians.ACP’s best practice advice addresses appropriate use of short course antibiotics in common infections.
Misgar RA, Mubarik I, Wani AI, Bashir MI, Ramzan M, Laway BA.Emphysematous pyelonephritis: a 10-year experience with 26 cases.Indian J Endocrinol Metab.2016;20(4):475–480. doi:10.4103/2230-8210.183475
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