What are Kidney Infections? Symptoms, Cause, Diagnosis and Treatment

Introduction to Kidney Infections

Kidney infections, also known as pyelonephritis, are a type of urinary tract infection (UTI) that often starts in the bladder and moves up to the kidneys. However, they can also occur if bacteria enter the kidneys directly from the bloodstream. Common symptoms include fever, difficulty urinating, pain in the lower back, and pain while urinating. Treatment typically involves antibiotics to remove the infection. 

This infection can affect one or both kidneys, depending on the severity. Pyelonephritis is generally more severe than lower UTIs and, in severe or untreated cases, can lead to serious complications such as permanent kidney damage. Taking antibiotics on time helps to recover from kidney infections timely. According to Cleveland Clinic, about an estimated 1 in 2,000 people suffer from kidney infection each year.

Understanding Kidney Infections: Its Causes and Risk Factors

Before diving into the causes and risk factors of kidney infections, learning about the Anatomy and Structure of the Kidney helps grasp how bacteria can affect this organ.

Bacterial Source of Kidney Infection

Kidney infection is usually caused by bacteria known as E. coli, which enter the urine tube (urethra), travel to the bladder, and then to the kidney. Cystitis is a type of UTI that potentially lead to pyelonephritis if untreated. 

While E. coli is commonly present in the bowel without causing issues, certain strains can cause harm. When it transfers from the bottom to the genitals during sex, it causes infections. While bacterial infection is the primary cause of kidney infections, certain conditions, such as a weakened immune system, uncontrolled diabetes, acute kidney injury, or kidney stones, increase the risk of developing infections.

Risk Factors of Kidney Infections

 

Women are more prone to developing kidney infectio

ns as compared to men because of their shorter urethra. It can devel

op at any age but is most commonly seen in younger women. This is due to the fact that younger women tend to be more sexually active and involved in frequent sex activity that increases the chance of kidney infections.

These factors are responsible for increasing the risk of kidney infections.

• More common in females: For women, it is easy for bacteria to travel from outside to the bladder due to their shorter urethra. Because the urethra is near the vagina and anus, it's easier for bacteria to get into the bladder and then into the kidneys. Pregnant women are more likely to suffer from kidney infections.
• Blockage in the urinary tract: The disruption in normal urine flow also leads to kidney infections. The blockage in the urethra causes incomplete excretion of urine from the bladder. It could be due to kidney stones, enlargement of the prostate gland, and narrowing of the urethra. 

• Weakened Immune System: Other complications like diabetes and HIV weaken the immune system, which can also be a reason for pyelonephritis. It also includes some long-term medicines taken for organ transplants to prevent rejection that results in a weaker immune system.

• Damaged nerves of the bladder:  Any damage in the nerve or spinal cord results in infection in the urinary bladder that travels to the kidneys.

• Use of urinary catheters: Urinary catheters increase the risk of kidney infections through bacterial entry and cause bladder irritation. These tubes empty bladders from urine and are usually used after any surgical procedure or diagnostic test. 

• Vesicoureteral reflux of urine: When vesicoureteral reflux causes recurrent UTIs towards the urinary bladder, it causes kidney infections. 

How is Kidney Infection Linked with Untreated UTIs?

A deeper understanding of Kidney Physiology and Function scan explain why untreated UTIs lead to more serious infections like pyelonephritis

When the urinary tract infection is not treated properly, it progresses to a kidney infection. The bacteria that causes UTI is not fully eradicated from the bladder that ascends towards the kidney, and its severity leads to a more severe infection termed pyelonephritis. 

Fever, back pain, and nausea are common symptoms of a developing kidney infection rather than just an untreated UTI. These symptoms may indicate that the infection has progressed from the bladder to the kidneys.

What are the Signs and Symptoms of Kidney Infection?

The symptoms of kidney infection include:

• Fever
• Chills
• Nausea and vomiting
• Frequent urination
• Pain while urinating
• Back or side pain
• The presence of pus or blood in the urine
• The cloudy smell of urine
• Stomach pain

The symptoms of kidney infection usually appear within a few hours of infection. The symptoms start from fever to side or back pain and increase with severity. The symptoms should be treated timely because they lead to sepsis and renal failure, which is a life-threatening condition. The severity of symptoms includes increased heart rate, rapid breathing, confusion, and hallucinations.

Transmission and Contagion

What is the Transmission Route of Bacteria

Bacteria cause kidney infections when they pass from the urinary tract to the bladder and then ascend from the bladder to the kidneys. The ureters (urine tubes) are the primary route of transmission of bacteria from the urinary bladder to the kidney. 

Escherichia coli (E. coli) is a bacterium that is naturally found in the digestive system and provides no harm. When this bacteria enters the urinary bladder from outside, it causes a kidney infection. The route of transmission of bacteria from outside involves:

• Sexual activity: Sexual activity can increase the risk of a urinary tract infection (UTI) due to the potential transmission of E. coli bacteria to the urethra. If a UTI is not treated, it may lead to a kidney infection, but sexual activity is not a direct cause of kidney infections.
• Improper hygiene practices are another transmission route for bacteria. Bacteria easily transfer from the genital area to the bladder due to inadequate cleaning.
• The use of catheters is another potential risk factor for the transmission routes for bacteria to cause kidney infection.

Are Kidney Infections Contagious?

Kidney infections are not communicable diseases and cannot be passed from one person to another.  There is a misconception that they can be transmitted through touch,  skin contact, or respiratory droplets. This is not true because kidney infections are only caused by bacteria if they enter an individual's urinary tract and bladder.

This is a common misconception about kidney infection because of other transmissible infectious diseases. "Infection" does not only mean that the disease is communicable. However, the bacteria that causes the infection (E. coli) can be transmitted under some circumstances.

The main cause is toilet hygiene and failure to clean genitals with water after using the washroom. This transmission does not cause a kidney infection in another person. It leads to a urinary tract infection (UTI), which, if not treated, leads to a kidney infection.

How to Diagnose and Treat Kidney Infections Effectively

Early and accurate diagnosis of kidney infections is necessary to prevent serious complications like chronic kidney failure or sepsis. It allows timely and effective treatment to reduce symptoms quickly and lowers the risk of repeated infection.

Moreover, early diagnosis also helps to avoid more intensive treatments. It leads to better long-term outcomes and cost-effective care. To diagnose a kidney infection, healthcare professionals usually take a medical history based on the symptoms. 

How is a kidney infection diagnosed?

The whole diagnostic procedure includes the following steps:

• Physical Examination: Physical examination includes heart rate, blood pressure, temperature, dehydration signs, and respiratory rate. It also includes assessment of mild to lower back pain, sensitivity, and tenderness.
• Pelvic Examination: In young females, doctors assess pelvic examination to identify asymptomatic pelvic inflammatory diseases. 
• Urine Sample: A midstream urine sample is taken to identify kidney infection. This test is performed in the lab, and the presence of bacteria and white blood cells indicates infection. Urinalysis and urine culture tests are performed with a urine sample. The turnaround time for a urine culture is about 24 to 72 hours. Both symptoms and lab results of urine help to diagnose kidney infection.
• Imaging: imaging is widely used to diagnose kidney diseases. Imaging methods include computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasound scans. These tests are performed in hospitals, and radiologists read and report on the images. The patient does not need anesthesia to perform these tests.

What are Preventive Measures to Minimize Transmission Risk of Kidney Infection?

Minimizing the risk of transmission of kidney infections is not difficult. Here are some simple steps to help prevent kidney infections. 

• Proper hygiene practices: It is recommended that they wash their hands thoroughly and their genital areas after using the toilet.
• Stay hydrated: Ensure proper hydration. Adults should drink 8 glasses of water to flush out bacteria through urine and prevent infection. 
• Urinate Properly: One should not hold urine for a longer time. Regular and complete excretion of urine helps clear bacteria from the urinary tract.
• Sexual hygiene: It is important to follow proper hygiene care practices after intercourse. Urination after sexual activity flushes out bacteria if the bacteria enter the urethra during sex.
• Ensure proper medication and treatment if diagnosed with UTI or kidney infection timely to prevent further complications. 

How to Treat Kidney Infections and Relieve Symptoms Effectively

What are the treatment options for kidney infections?

1. Antibiotics for Kidney Infections
   

   Antibiotics are the primary solution to treat kidney infections. The selection of antibiotics and duration of treatment depend on the patient's health and the bacteria found in the urine test. For proper treatment, patients with kidney infections are prescribed a course of antibiotic tablets or capsules for about 7 to 14 days.
   During the course, the symptoms start diminishing within a few days of treatment. However, the patient will be asked for a repeat urine culture test to ensure complete infection removal. Some severe kidney infections require prompt treatment to stop the infection and prevent kidney failure and infection from spreading to the bloodstream. If the infection still continues, a patient needs to take another course of antibiotics.

2. Painkillers for Kidney Infections
   

   Painkillers are also required for pain removal in kidney infections. Paracetamol is highly recommended to relieve pain symptoms and high temperatures. Anti-inflammatory drugs, including ibuprofen (NSAIDs), are not prescribed because these drugs can worsen kidney function in patients with an existing kidney infection. It is recommended to advise the general physician to resolve further concerns associated with kidney infection.

3. Hospitalization Considerations
   

   The patient with vulnerable effects of infection like pregnancy, long-term health conditions, or other complications needs to be admitted to the hospital. It requires antibiotic treatment through intravenously (IV) drip. 
   
   Patients with an early diagnosis of kidney infection and treated promptly with antibiotics feel better after 2 weeks. People of older ages and having underlying conditions take longer to recover. The duration of stay in the hospital depends on how severe the infection is. 
   
   The patient will be assessed with regular blood and urine tests to monitor the health and the effectiveness of the antibiotics in fighting the infection. The majority of patients with kidney infection respond well to IV treatment.
   
   As long as there are no complications, the patient typically recovers enough to leave the hospital in 3 to 7 days. However, recovery times vary based on the severity of the infection and the patient’s overall health. Hospital treatment may also be needed if:
   
   
   • The patient is severely dehydrated.
   • The patient is unable to swallow any food, fluids, or medicines.
   • Patient with severe kidney pain and blood in the urine.
   • The symptoms fail to improve within 24 hours of taking antibiotics.
   • Patient having a weakened immune system
   • Patients with kidney stones or catheters in the urinary tract.
   • Patients have an underlying condition like polycystic kidney disease or chronic kidney disease.
   • If a pregnant woman experiences a high fever, it is a serious concern that requires medical attention. It indicates a kidney infection or another type of infection that needs to be addressed promptly.
   • The patient shows additional symptoms of blood poisoning, like rapid heartbeat and unconsciousness.

4. Home Remedies and Self-Care Practices to Relieve Symptoms.

Besides treatment with antibiotics and painkillers, home remedies and self-care practices also play an essential role in reducing symptoms of kidney infection. Following practices at home is considered beneficial for kidney infections.

• • Drink plenty of fluid to flush out bacteria from infections. Also, avoid coffee and alcohol until the kidney infection has cleared. It worsens the feeling of urinating.
  • Take sufficient rest for kidney infection disease. Even if the patient is normally healthy and strong, a kidney infection can be physically draining. It takes up to 2 weeks to fully recover and return to work.
  • Place a heating pad on the stomach, back, or side to ease pain.
  • Consume painkillers like paracetamol to relieve severe pain from kidney infection. Consider taking pain relievers like acetaminophen (Tylenol), which is the best option for fever or discomfort.
  •  If the patient suffers from chronic kidney disease, it's best to avoid nonsteroidal anti-inflammatory drugs (NSAIDs), including ibuprofen (Motrin IB, Advil, others).

Complications and Risks

If kidney infections are not treated properly on time, they cause serious complications. 

• Kidney abscess: If not treated properly, a kidney infection can lead to a kidney abscess, which collects pus inside the kidney tissue. This occurs when the bacteria spread to other parts of the body, potentially causing complications in the lungs and bloodstream.

• Blood poisoning (septicemia): When a bacteria from a kidney infection enters the blood, it results in septicemia (poisoning of blood). The poisoned blood spreads through the body into all organs. It is a medical emergency that needs prompt treatment. 

• Severe infection: The untreated kidney infection leads to severe infection, also termed emphysematous pyelonephritis. It damages the kidney tissue and builds up toxic gas in the body. It mostly occurs in diabetic patients. 

• Kidney failure. The untreated symptoms of kidney infections lead to kidney failure. 

• Gestational Complications: Kidney infection in pregnancy causes severe complications. Pregnant women have a chance to suffer from breathing problems known as adult respiratory distress symptoms and early onset delivery. 

Differences Between UTIs and Kidney Infections

It is important to understand the difference between UTIs and kidney infections for proper management and treatment. Both conditions have similar symptoms, but kidney infections are more severe than UTIs.

Untreated urinary tract infections and UTIs lead to serious health complications. The UTI causes discomfort, which is generally less severe and easier to treat.

It is necessary to recognize the signs of a kidney infection, such as a high fever, back pain, and nausea. It requires intensive and prompt treatment, sometimes even hospitalization.

While, on the other hand, mild UTIs are easily managed with oral antibiotics and increasing the fluid intake.

 

Aspect	Urinary Tract Infections (UTIs)	Kidney Infections
Location	Affects the lower urinary tract (urethra and bladder)	Affects the upper urinary tract (kidneys)
Common Symptoms	Frequent urge to urinate Burning sensation during urination Cloudy or strong-smelling urine Lower abdominal pain	High fever Chills Nausea and vomiting Pain in the back, side, or groin Symptoms of a UTI (frequent urination, pain)
Severity	Generally mild but uncomfortable; it usually doesn’t cause long-term damage.	More severe, it can lead to kidney damage or sepsis if untreated
Treatment	Oral antibiotics Pain relievers Increased fluid intake	Stronger antibiotics (often IV in severe cases) Hospitalization Longer treatment duration
Complications	Rare, but causes kidney infection if untreated	It can cause permanent kidney damage, high blood pressure, or sepsis
Who’s at Risk?	More common in women, especially those who are sexually active	Anyone with untreated UTI, urinary blockages, or weakened immune systems

Table 1: Differences Between UTIs and Kidney Infections

 

Preventing Kidney Infections: Tips for Maintaining Kidney Health

Preventive measures are essential steps to help prevent kidney infection. It includes hygiene and lifestyle recommendations, medical interventions, and risk reduction strategies. 

What steps can be taken to prevent kidney infections?

Hygiene and Lifestyle Recommendations 

Most kidney infections result from preexisting urinary tract infections (UTIs). Hygiene and safety measures are the best way to prevent infection from the urethra or urinary bladder. Here are some tips to avoid infection by considering hygiene practices.

 

• Hydration: Drink sufficient amounts of fluids, particularly water, to flush out bacteria through urine.
• Urination: Do not hold urine for a longer period of time. Urinate whenever there is an urge to excrete. 
• Sexual intercourse: Follow proper hygiene practices and always urinate after sexual intercourse. It is recommended to wash the genitals before and after having sex.
• Hygiene: Properly wash the genitals every day after using the washroom. Avoid using deodorant sprays or a douche to clean the genitals.
• Toilet hygiene: Properly wipe the anus from front to back after passing stools. It reduces the risk of spreading bacteria to the genitals.
• Fiber: It is recommended that a sufficient amount of fiber be taken so that stools can excrete out easily and do not cause irritation or skin lesions. Constipation increases the chance of developing a kidney infection, and decreased fiber is linked with kidney stones.

Medical Interventions

Medical interventions are also prescribed for the proper treatment of kidney infections. It includes

• Vaccinations: Vaccination is recommended for high-risk individuals, such as people with urinary tract infections (UTIs) or compromised immune systems. They should discuss available options with their doctor.
• Prophylactic Antibiotics: Some patients are also prescribed a low dose of antibiotics to prevent repeated infections, especially in cases of frequent UTIs.
• Follow-up: Regular medical follow-ups are essential for early detection and treatment of potential issues in cases of a history of kidney infections.

Risk Reduction Strategies

Risk reduction strategies and management for kidney infection include dietary adjustment, managing chronic complications, and avoiding harmful substances. 

Can a kidney infection lead to chronic kidney disease?

Yes, if the kidney infection is left untreated, it leads to chronic kidney infection. The following risk factors regarding kidney infection include

• Dietary Adjustments: For kidney infection patients, it is recommended to limit salt intake, increase fluid intake, and eat a balanced, healthy diet. Excess salt strains the kidneys and decreases their functionality. Increased fluid intake helps prevent bacteria from sticking to the walls of the urinary tract and flushing out through urine. Also, focus on a diet rich in fruits, vegetables, and whole grains. These foods support overall health and immune function, reducing the risk of infection.
• Manage Chronic Conditions: The proper management of complications like diabetes and hypertension is vital. This is because these can increase the risk of kidney infections.
• Avoid Harmful Substances: Limit the use of substances that can harm the kidneys, such as NSAIDs (non-steroidal anti-inflammatory drugs), excessive alcohol, and tobacco intake.

Myths and Misconceptions

How do kidney infections relate to urinary tract infections (UTIs)?

A UTI is linked with the urinary tract, which includes infection in the kidneys and tubes (ureters) that connect the kidneys to the bladder. Kidney infections involve the infection of only the lower urinary tract: the bladder (where urine is stored) and the urethra tube that excretes urine. 

There is much information surrounding the internet regarding kidney infection, but not all information is accurate and reliable. Here are some common myths and misconceptions highlighted with accurate truth about kidney infection and UTI. 

Myth 01: Only women can get a urinary tract infection.

Truth: This myth is wrong because UTIs can affect both men and women. The UTI in men is often more complicated and can involve the prostate. However, women are at greater risk for a UTI due to the shorter urethra in women than in men. It is easier for bacteria to travel to the bladder and cause infection. UTIs are also more common in postmenopausal women due to decreased estrogen levels that change vaginal and urethral tissue and increase the risk of infection.

Myth 02: All UTIs cause symptoms.

Truth: It is also a misconception that all UTIs cause symptoms. Mostly, UTIs show symptoms, including pain or burning while urinating, but all do not show. They also make patients feel that they need to urinate often. However, other UTIs could be due to bacteria in the urinary tract but do not show any symptoms. They are more prevalent in older adults or those who use a catheter to empty their bladders. UTIs without showing symptoms are the result of asymptomatic bacteria.

 

Myth 03: All UTIs must be treated with antibiotics.

Truth: It is not necessarily true that all UTIs require antibiotics for treatment. Some people do not show any symptoms of UTI but have bacteria in their bladder due to asymptomatic bacteria. In this case, no treatment or antibiotics would be recommended as the bacteria is not causing issues.

However, in cases of UTI in pregnant women, people with planned urologic surgery and weakened immune systems may require proper treatment. Antibiotics are used to treat UTIs. They are recommended when a person shows painful symptoms due to bacteria in the urine.

Myth 04: A UTI will go away on its own.

Truth: Not all UTIs are treated without medicine. A UTI caused by bacteria that don't show any symptoms might go away on its own without needing treatment. However, UTIs with symptoms require proper treatment and rarely resolve on their own.

If a person is experiencing UTI symptoms, like a burning sensation and pain while urinating, they should visit a healthcare team to obtain a urine culture and the proper treatment.

Myth 05: UTIs are contagious and can be passed to your partner.

Truth: UTIs aren't spread through sexual activity or physical touch with others.

Myth 06: UTIs are sexually transmitted infections.

Truth: This is somehow a wrong misconception. Sexual activity increases the risk but does not cause a UTI. Therefore, UTIs are not considered sexually transmitted infections (STDs).

During intercourse, bacteria can travel into the urethra, which is the small tube that carries urine out of the bladder. To lower the risk, try urinating after sex to flush out some of the bacteria before it can lead to an infection.

When to Seek Medical Help

In severe cases, it is important to seek medical help to prevent further health-related complications. If someone observes severe symptoms related to a UTI or kidney infection, consult a doctor. Also, go to a healthcare provider if someone is being treated for a UTI, but the symptoms aren't getting better.

The negligence in symptoms leads to severe complications, including blood poisoning, damage to body tissue, renal failure, or even death. So, a patient should immediately consult with a doctor in the following cases: 

• High-grade fever due to kidney infection
• Severe nausea and vomiting due to infection
• No improvements in symptoms with antibiotics
• The patient has a health condition or a weak immune system.
• Women are having kidney infections and are pregnant.

Conclusion

UTI is the primary cause of kidney infections, which can also result from various other conditions. Females of all ages and males over 65 are more prone to kidney infections. Most kidney infections resolve themselves with plenty of fluids and water and a course of antibiotics, but some people may require additional treatment. 

They can also reduce the chances of kidney infection through proper maintenance of good hygiene and clean toilet habits after passing stools, wiping the anal from front to back after passing stools, and urinating and washing the genitals after sex. 

If a person suspects a kidney infection, consult a medical professional. Some infections can lead to more severe conditions that require immediate hospital treatment to prevent further complications.