Kidney Infection: Symptoms, Causes, and Treatment

Have heard of pyelonephritis? Pyelonephritis refers to infections in the kidney, occurring due to entry of bacteria through the urinary tract. The bacteria then travel up the urethra and finally affect your kidneys. People especially with bladder infection, pregnancy, or mostly females are more likely to develop kidney infection.

Untreated kidney infection may spread to other parts of the body, or cause permanent damage to the kidneys. This is why people experiencing symptoms of kidney infection must seek prompt medical attention to avoid such complications. Look into this blog to discover more on causes, signs, diagnosis, treatments and prevention of kidney infection.  

What is kidney infection?

Kidney infection, also known as pyelonephritis, is a type of UTI (urinary tract infection) which is caused by bacteria moving across your body, like over your bladder, and up to the kidneys. The entry of bacteria in your kidneys might damage either of them or both the kidneys. Visit a healthcare provider immediately once you notice signs of kidney infection. 

Kidney Infection Symptoms

Symptoms for kidney infections typically develop within a few hours to some days.

Some common signs of kidney infection are:

• Fever or persistent high temperature, reaching up to 103.1 degrees Fahrenheit or 39.5 degrees Celsius
• Fatigue, feeling of constant tiredness and weakness
• Feeling sick
• Diarrhoea
• Nausea, vomiting, loss of appetite
• Chills and shivering
• Discomfort and pain in the side, groin, abdomen, lower back, or around the genitals

If you have urethritis or cystitis apart from kidney infection, you might also experience additional symptoms like:

• Frequent and urgent urge of urination
• Appearance of blood in the urine
• Pain in lower abdomen
• Confusion
• Cloudy urine with a foul smell
• An incomplete feeling of totally emptying the bladder during urination
• A burning sensation associated with pain while urinating

On the other hand, children with kidney infection exhibit symptoms such as:

• Irritability
• Growth rate is not as expected
• Jaundice, a condition having white eyes and yellowish skin
• An unpleasant smell from urine
• Bedwetting
• Appearance of blood in the urine
• Abdominal pain
• Poor feeding and vomiting
• Lack of energy

Males vs. Females

Although both males and females show similar symptoms during a kidney infection, females are usually more prone to developing the infection. This is mainly due to the typically shorter size of urethra in females than males. This makes the anus and vagina closer to the urethra in a female. The bacteria can then easily enter the body through the urinary tract. In fact, pregnant females are usually more prone to develop a kidney infection or an UTI.  On the contrary, a male aged below 65 years might develop conditions like UTI.

What causes kidney infection?

Bacteria entering the urinary tract through the urethra multiply several times and reach the kidneys. It is the primary cause behind any kidney infection.

However, the bacteria or viruses causing kidney infections might come from other parts of the urinary tract, including the urethra, bladder, or uterus, and gradually spread to the kidneys. Bacteria might also travel to the kidneys through bloodstream. Infection of a heart valve or an artificial joint might act as rare causes of kidney infection.

Blockage of your urine flow through the urinary tract might also result in kidney infection. This might happen because of:

• An enlarged prostate
• Stones in the kidney
• Issues with the shape of your urinary tract, making it difficult for urine to pass through

Some bacteria causing kidney infection are:

• Proteus mirabilis
• Staphylococcus
• Enterobacter
• coli.

However, there is no worry of transmission of kidney infection from one individual to other as this is a non-contagious disease.

Conditions and Diseases Occurring from Kidney Infection

Bacterial infection

Pyelonephritis suggests urine infections or UTIs with direct involvement of the kidneys. The bacteria post-streptococcal glomerulonephritis is typically noted for remote infection leading to kidney disease. This usually occurs after an infection in the throat or some other part by the bacteria Streptococcus. It is the most common cause leading to glomerulonephritis worldwide. Although it goes away on its own, it primarily targets children. It is also common in older individuals, especially in underdeveloped countries, and does not easily recover.

Glomerulonephritis might also be caused by other bacterial infections including heart valves, infected lines, and some inflammatory infections at times. These issues mostly occur in developed countries where Streptococcal infection is not necessarily the cause.

Tuberculosis

Typical affecting of the kidney by tuberculosis gradually over months leads to a condition called chronic interstitial nephritis. It might lead to scarring of your bladder or uterus lying below the kidney. Due to its slow progression, it is often diagnosed lately. This is there is lasting damage despite available treatment. 

Viruses

Again, the virus Hepatitis B can lead to Membranous Nephropathy, while MPGN (another kind of glomerulonephritis) is typically caused by Hepatitis C or by cryoglobulinaemia (a type of vasculitis) at times. All these viruses are responsive to antiviral treatments. However, kidney disease usually takes long to improve, resulting in lasting damage.

HIV, on the other hand, can also be responsible for a variety of kidney diseases. Some other viral infections or autoimmunity due to infections might also be the cause. One of the rare viruses known as the Hantavirus is reported to cause a less common kidney infection, an acute interstitial nephritis.

Parasites

Malaria caused by parasites might also lead to acute kidney injury during severe infections, or might even lead to glomerulonephritis. Another rare type of parasitic infection called Schistosomiasis, usually found in fresh water is also reported to infect the bladder. As a result, it scars the ureters and the bladder, and end up in damaging the kidneys.

Leptospirosis, another typical parasitic infection is known to cause fever along with red eyes, acute injury of kidney(s), ad jaundice. Rodents such as rats usually spread this parasite through sewers, rivers, or other water resources. 

Risk Factors

Kidney infections are quite rare conditions. Every single person out of every 830 people in the UK is estimated to develop a kidney infection every year. Kidney infection might occur at any age, but are typically more common in females. In fact, women are 6 times more prone to develop kidney infection as compared to men.

Moreover, younger females who are sexually active are more susceptible to the risks of kidney infection. This is basically due to their frequent involvement in sexual activities which increase their chances to catch kidney infection. Here are the risk factors making you more vulnerable to kidney infections:

• Being female: Women have a shorter urethra than men. This is why bacteriacan easily enter the bladder from outside the body. This makes the anus and the vagina close to the urethra, allowing on easy invasion of bacteria into the body. After entering the bladder, the bacteria can easily spread to the kidneys. Pregnant women, for this reason, are more vulnerable to risks of kidney infection.
• Having a blockage in the urinary tract: You might be more prone to the risks of kidney infection if you face issues with emptying the bladder completely, or suffering from a slow flow of the urine. This might result from narrowing of the urethra, a stone in the kidney, or enlargement of the prostate gland.
• Having a weak immune system: Certain medical conditions such as HIV or diabetes can make your immune system weak. Medications for these problems also reduce your immunity.
• Damage of the nerves surrounding the bladder: Damage of your spinal cord or nerves can block your ability to sense an infection in the bladder. This restricts your body from realising when the infection reaches up to your kidney.
• Using a urinary catheter: Tubes draining urine from the bladder are known as urinary catheters. Catheters are usually used after a diagnosis or some surgical procedure. These are usually helpful for patients confided to bed.
• A condition of urine flowing in the reverse way (vesicoureteral reflux): Vesicoureteral reflux involves reverse flowing of small quantities of urine from the bladder back to the connecting tubes of bladder and kidneys. People having this condition are extremely vulnerable to risks of kidney infections, both at childhood and at adulthood.

Complications

If prompt medical action is not taken against kidney infection, risks of serious complications may include:

• Emphysematous pyelonephritis (EPN): It is a rare complication, but potentially turn fatal. EPN refers to a serious infection where the kidney tissue is damaged by necrotising bacteria. Vomiting, nausea, abdominal pain, fever, or confusion – all can characterise this condition. Especially females with diabetes are more likely to get this condition. Surgery may be effective in such conditions.  
• Kidney abscesses: Accumulation of pus in kidney tissues leads to abscesses. From weight loss to appearance of blood in urine to abdominal pain, all can be significant symptoms. While surgery can drain out this pus, diabetes, pregnancy, or kidney stones can be serious risks.
• Acute renal failure: This might stop the functioning of one or both the kidneys. Before treatment begins to be effective, a dialysis may be necessary in such case.
• Renal vein thrombosis: Blood clot occurring in any of the major kidney veins can lead to lack of blood supply to the kidneys. It leads to chronic kidney disease or acute kidney injury.
• Sepsis or blood poisoning: Sepsis is a condition of medical emergency which requires swift medical diagnosis and treatment. It might cause a drop in a person’s blood pressure, and affect blood circulation. As a result, blood moves slowly and results in clotting within the blood vessels. In fact, improper circulation of blood might also lead to kidney failure at times.

How to diagnose a kidney infection?

Firstly, a medical professional will go through your medical history to look for conditions which can be linked with kidney infection. Some common diagnostic processes to evaluate your kidney infection include:

• Physical assessment: A physical assessment is the very first step a medical professional would take to get a thorough check of your general state of health. This might include measuring your blood pressure, heart rate, signs of dehydration, temperature, or respiratory rate. Your healthcare provider would also check your mid to lower back to detect signs of tenderness, pain, or sensitivity.
• Rectal examination: In case of a male patient, the doctor usually looks for enlargement of the prostate gland which blocks the bladder. This process is called the digital rectal examination.
• Pelvic examination: In case of a patient being a young female, the medical professional might also conduct a pelvic test to check if there is any asymptomatic pelvic inflammatory disease. A pregnancy test is also important for a female patient.
• Urine test: Your healthcare provider will collect your mid-stream urine sample in a special container for analysis in the laboratory. If your urine sample is tested to contain white blood cells and bacteria, it might be sign of an infection. Both the symptoms and lab test results would further guide the diagnosis.
• Imaging techniques: Your doctor might also recommend imaging of your kidney area through CT scan, ultrasound, or MRI scans to get a clearer visual of your kidneys.

Treating Kidney Infections

An individual who is suspected to have kidney infection would definitely require a urine test. The typical course of treatment for a kidney infection includes antibiotics. However, other forms of treatment might be required for more complicated cases.

• Antibiotics

If an individual exhibits symptoms of an infection, the doctor prescribes antibiotics even before receiving the test results. Pain relievers might also be recommended in cases of painfulkidney infection. The patient must finish the entire course of antibiotics. After receiving the test results, the medical professional might change the antibiotic as per the patient’s health report, and suggest the one which will be more effective in treating the infection.

Prescription of the antibiotic depends on the individual patient case and his/her medical history, and individual patient case. While some patients are sensitive to certain antibiotics; the primary treatment begins with a general antibiotic, and then slowly advances to a stronger dose. 

• Fluids

Consumption of plenty of fluids is essential for patients having kidney infection. This helps prevent risks of dehydration and fever. Recommendations of fluid intake may, however, vary from patient to patient as per their type of infection.

• Hospital treatment

If the symptoms of an individual do not improve with the former two treatments, hospitalising the patient might help managing the severity of the infection. Treatment in a professional setting like a hospital might include intravenous administration of the antibiotic through the vein in the arm of the patient.

If the person is suffering from serious dehydration, administration of fluid with a drip might help. However, most cases of hospitalisation do not extend beyond 3 to 7 days.

• Surgery

A patient having an enlarged prostate or a kidney stone might suffer blockage of the urinary tract. Surgical options prove to be the most effective treatment in such cases.

Tips for Prevention

However, you can minimise your risks of developing a kidney infection or UTI by taking some proactive approaches. Females particularly can reduce their risks by:

• Drinking plenty of fluids, mainly water, to remove bacteria from the body and pass them with urine.
• Immediately go for urinating as soon as they experience the urge to, as delayed urinating can be risky.
• Make sure to urinate after having a sexual intercourse. This is because urinating or emptying the bladder after a sexual activity helps clear bacteria from the urethra and bladder, lowering the risks of infection.
• Do not forget to wipe carefully, from front to back, after urination or after a bowel movement. This prevents spreading of the bacteria in the urethra.
• Do not use products like douches or deodorant sprays in your genital areas as these might act as irritants.

Kidney Infection and Pregnancy

Occurrence of UTIs (urinary tract infections) are quite common during pregnancies. This increases your risks of developing a kidney infection. Remember that untreated or delayed infections can lead to problems for both the growing baby as well as the mother’s health. It might lead to complications like:

• The baby being born too small
• Lung problems causing difficulties for you to get sufficient oxygen
• Damage of the kidneys
• Premature delivery of the baby before due date

When to see a doctor?

If you notice severe signs of illness or dehydration, or any of the following signs, make sure to see a doctor promptly:

• Unable to pee or urinate in very little quantities
• Severe shortness of breath
• Mental changes and confusion
• Sudden outbreak of pain or fever

Questions to ask your healthcare provider

Once you are visiting a healthcare professional, make sure to ask the following questions:

• How to take the medications?
• How to prevent risks of kidney infections in the future?
• What to do at home to get better?

Key Takeaways

Prompt treatment of kidney infections limits the rate of serious conditions. Proper emptying of the bladder and practise of good hygiene can help prevent risks of UTIs travelling up to the kidneys. If you are facing an underlying condition which might develop into an infection, consult your healthcare provider for preventive measures.  

FAQs

How does a kidney infection develop?

The kidneys form urine to pass away the waste materials. This urine travels through tubes called ureters and then to the bladder, a pouch holding your urine until you go to the bathroom. From the bladder, the urine moves on to another tube called the urethra to finally leave your body. This urine carries away the bacteria and other germs along with it.

At times, the bacteria can move upwards into your body and cause infection of your urinary tract including your bladder, ureters and the urethra. They further travel into one or both of your kidneys from there, standing out as significant reasons for kidney infection. Moreover, bacteria entering your blood from any other body part might also infect your kidneys.

How do I know I have kidney infection?

If you observe early signs of kidney infection such as dark and cloudy pee with blood appearing in your urine, or feel a painful and burning sensation while urinating, it might indicate kidney infection. A foul smell emitting from your urine, a constant and frequent urge to urinate, an incomplete feeling of emptying the bladder, chills, fever, or pain in the groin, or lower back – all these point towards signs of kidney infection.

Are kidney infection and urinary tract infection (UTI) the same?

A kidney infection is actually a type of UTI (urinary tract infection). But by UTI, people mostly mean infection in parts of the lower urinary tract such as the urethra or the bladder. A kidney infection and lower UTI have many similar symptoms, but a kidney infection is typically more serious. It might make you feel sick, cause fever, or severe pain in your lower back or groin.

How long does kidney infection last?

A right treatment might help you recover from a kidney infection and make you feel better within a few days. But if you have severe kidney infection symptoms, it might last for several weeks.

Can a kidney infection heal on its own?

While lower UTIs usually heal on their own in most cases, kidney infection can actually lead to serious complications if left untreated. Consult a healthcare provider as soon as you notice signs of kidney infection.

How to deal with kidney infection at home?

Drinking plenty of fluids (especially water) and avoiding caffeine and alcohol can help your kidneys fight the infection. But remember that home remedies are not enough. You must follow the doctor’s prescribed medications and antibiotics for best health results beside practising home care.

Is it safe to have sex during ongoing treatment of kidney infection?

Once you have started treatment of your kidney infection and your symptoms have started going away, you can definitely have sex. But remember to have protected, safe sex and make sure to pee after an intercourse to get rid of bacteria present in your urinary tract.