Kidney Infections: How are they caused?

A kidney infection (pyelonephritis) results from a urinary tract infection (UTI) that begins in the urethra or bladder and travels to one or both of your kidneys.  

Kidney infection tends to occur when a UTI is  left untreated or is particularly virulent. You can check out our article on urinary tract infections to learn more. 

Treating a kidney infection is possible, and your doctor will usually prescribe antibiotics to help your immune system to clear the infection. However, if left untreated, the infection can progress and worsen. A severe kidney infection can cause life-threatening illness (sepsis) or permanent kidney damage. 

If you or someone you know has symptoms of a kidney infection, it’s vitally important that they seek urgent medication attention before the condition worsens. 

Keep reading to find out how to spot the signs of a kidney infection, learn and prevent potential causes and understand how to treat it. 

Kidney infection symptoms

The signs of a kidney infection can appear within just a few hours of a urinary tract infection (UTI). There are several initial signs you may notice, including: 

• Shivering 
• Fever 
• Nausea 
• Pain in the back 
• Pain in the flanks (sides of the torso) 

In addition, typical symptoms of a urinary tract infection, can also be present. These include: 

• The urge to urinate more than usual 
• Pain or a burning sensation when urinating 
• Smelly or cloudy urine colour 
• Blood in your urine 

If you are worried about your urge to urinate resulting in little leaks, then be sure to look at TENA’s full range of incontinence products. We also have incontinence products for men and women available in a range of sizes and fits and suitable for varying levels of incontinence. 

Kidney infection causes

So, how exactly do you get a kidney infection? There are a couple of causes. 

1. Urinary tract infections are one of the main causes of kidney infection. UTIs occur  when bacteria gets into the urethra (the tube that carries the urine out of your body). Bacteria travel up the urinary tract to your bladder, which can in turn causes cystitis. The bacteria can then progress up into the kidneys, thus causing a kidney infection. Kidney infections affect women more often than men due to differences between the male and female body. A woman’s urethra is shorter, meaning it is easier for bacteria to find its way into the urinary tract and reach the kidneys. 
   
   
2. Kidney stones, diabetes or a weakened immune system can also result in a kidney infection. These are examples of causes that don’t directly involve a bladder infection, but that can increase the likelihood of a kidney infection occurring.

Diagnosing a kidney infection

To work out whether you have a kidney infection, your doctor will ask you about your symptoms and recent medical history.  
  
Standard procedure for diagnosing a kidney infection involves carrying out a urine test to see whether you have a UTI.  

However, if you are male with a confirmed UTI, a GP will refer you straight to a urologist for further investigation as it quite uncommon for men to contract kidney infections and it may be a sign of another underlying condition. 

How to treat a kidney infection 

Antibiotics

Treating a kidney infection is often achieved by using antibiotics. They help give your immune system the tools to overcome the infection, and while they can take some time to work, they are effective.

Painkillers

Kidney infection pain relief is important to keep you as comfortable as possible while you get further diagnosis and treatment. Painkillers can’t resolve the infection, but they can help you manage kidney infection symptoms. Paracetamol, taken up to 4 times a day, can help reduce the pain and high temperatures. Paracetamol is usually recommended over ibuprofen or aspirin. 

How long does it take to recover from a kidney infection? 

Recovery time from kidney infection may vary depending on its severity. Symptoms might start to clear up within a few days of treatment, but you may still need to take antibiotics for a week or so after, and it’s important that you finish the full course of antibiotics to totally eradicate the infection. Most people who receive treatment promptly will feel better again after 2 weeks, however those with pre-existing conditions may take longer to recover. 

Kidney infection: when to go to hospital

If your kidney infection symptoms don’t subside after 24 hours of taking antibiotics or if you have a weakened immune system, you may be admitted to hospital and treated with antibiotics through a drip.  

There are some additional instances in which you should go to hospital, including: 

• if you have kidney stones  

• You have a urinary catheter 

• You have diabetes or an underlying condition such as polycystic kidney disease.  

This is because doctors need to take extra precautions if you are vulnerable to infection. Children and people aged over 65 with a kidney infection are also recommended to go to the hospital. 

Kidney infection during pregnancy – When to worry

Getting a kidney infection during pregnancy can be quite dangerous as it may cause you to go into labour prematurely or to have a low birthweight baby. Therefore, it is important to catch it soon and start treatment promptly.  

You might be more likely to get admitted into hospital as doctors can take urine and blood samples regularly to help monitor your condition. You’ll also be advised on the best antibiotics to take during pregnancy which, if you’re admitted to hospital, will probably be administered to you through a drip. 
  
Feeling a frequent and painful need to urinate is one of the symptoms of kidney infection particularly associated with pregnancy. However, it is important to remember that the baby’s weight and pressure on your bladder can also cause an urge to use the toilet more often as well, so why not take a look at our guide on pregnancy and incontinence for more information? 

What to eat and drink with a kidney infection

Your diet can play a role in how quickly you recover from a kidney infection. Learn what to avoid consuming with a kidney infection and what is recommended to eat or drink: 

1. Drink plenty of water. 

2. Avoid alcohol and coffee – kidneys help to filter out certain compounds in caffeinated drinks. Drinking these liquids might require the kidneys to work harder, which will put added strain on them and could affect your healing process. You might now be wondering: can alcohol cause a kidney infection? The answer is no, there’s no conclusive evidence of this but drinking alcohol while suffering from a kidney infection is definitely not recommended for the same reasons mentioned earlier. 

3. Take probiotics once you’ve finished your course of antibiotics – Antibiotics can affect the “good” and “bad” bacteria that your body needs to function, particularly in the gut. Eating probiotics will help to restore a healthy balance of the important bacteria your body needs to stay healthy. 

4. Try vitamin C – its antioxidant properties help protect the body from oxidative stress which can promote kidney health. 

Tips to prevent a kidney infection 

To prevent kidney infections in the future, there are a few steps you can take: 

1. Stay hydrated throughout the day, particularly if you exercise or do manual work. 

2. Keep your genitals clean (especially after going to the bathroom).  

3. You should always wipe from front to back to reduce the chance of bacteria entering the urinary tract. 

4. Urinate after having sex.  

We hope you have found our guide on the signs and treatments of kidney infections useful. If you are struggling with other bladder related issues, be sure to take a look at our full selection of articles. We cover everything from overactive bladder syndrome to neurogenic bladders.