When many people think of a urinary tract infection (UTI), they often think of a bladder infection. Although that’s one common type of UTI, the bladder is actually not the only possible site of a UTI. There are also other parts of the urinary tract that may become infected, including the kidney. A kidney infection occurs when bacteria make their way up from the bladder to the kidney. Kidney infections are also a type of UTI, but are more serious than a bladder infection. The medical term for a kidney infection is pyelonephritis.
What are the first signs of a kidney infection? Can a kidney infection kill you, and what can be done to treat it? How can you know whether you have a bladder or a kidney infection?
Frequent Kidney Infection Causes
In most cases, a kidney infection starts as a bladder infection. This occurs when bacteria grow inside the bladder. From there, the bacteria can move up the ureter, which is the tube that connects the kidneys to the bladder. The infection can then reach the kidneys, leading to a kidney infection.
Women are at a greater risk than men for all types of UTIs. This is because the urethra, or the tube that carries urine from the bladder out of the body, is shorter in women, so it’s easier for bacteria to make their way up it. Having frequent sex also increases the risk for UTIs in women, because sex can push bacteria towards the urethra and make it more likely that the bacteria will enter it. Anything that impairs the immune system (including diabetes) or reduces the flow of urine can also lead to UTIs. Untreated kidney stones increase the risk of a kidney infection.
Are kidney infections common?
Most people who get a bladder infection will not end up with a kidney infection. It’s estimated that kidney infections affect 15 to 17 per 10,000 women per year in the US. Pregnant women experience pyelonephritis at higher rates than other populations; a kidney infection occurs in about 1 to 2% of pregnancies.
Kidney Infection Symptoms
A kidney infection can be considered a form of “extreme UTI,” symptoms of which are very similar to those of the more common UTI, a bladder infection. The symptoms of a kidney infection tend to come on quickly, and often people will go from feeling normal to feeling very sick within hours. Some of the early signs of a kidney infection may include:
- Cloudy urine
- Pus or blood in the urine
- Needing to urinate very frequently
- Burning with urination
There are also some other symptoms which may accompany a kidney infection, including pain and digestive symptoms.
Infection in kidneys causing back pain
The kidneys are located just under the rib cage, in the middle of the back. During a kidney infection, pain from the kidneys can often be felt in the back. Some people feel pain from a kidney infection in their side or in their groin, so if you don’t have pain in your back, this doesn’t necessarily mean that you don’t have a kidney infection.
Kidney infection and loss of appetite
As with many other serious infections, a kidney infection can cause a loss of appetite. Nausea and vomiting are also common symptoms that may occur with a kidney infection.
Kidney Infection Treatment
Antibiotics are used to treat a kidney infection. In most cases, you will get a course of antibiotics to take by mouth at home. However, in more severe cases, people with kidney infections sometimes need to be admitted to the hospital and given antibiotics through an IV.
It’s important to get treatment for a kidney infection; left untreated, it can become dangerous. In some cases, the bacteria can spread from the infected kidney into the bloodstream, a condition known as sepsis. An untreated kidney infection can also cause permanent damage to the kidney. This can then lead to chronic kidney disease, which progresses through several stages and can eventually become life-threatening.
Although people sometimes wonder how to clear up a kidney infection on their own, the truth is that this is very dangerous, and getting treatment with antibiotics is important to protect yourself from long-term kidney damage and even life-threatening sepsis.
How to know if you have a urinary tract infection?
A urinary tract infection (UTI) occurs anywhere along the urinary tract, from the bladder up to the kidneys. However, the most common type of UTI is a bladder infection. 1 in 5 women will experience this type of UTI at least once in their lifetimes.
Symptoms, such as burning with urination, are common with UTIs. However, similar symptoms can also be caused by many STDs (such as gonorrhea and chlamydia) as well. In order to figure out the cause of your symptoms so that you can receive the right treatment, testing is needed.
A urine sample can be used to test for a UTI as well as several different STDs. You can go to a laboratory or to your doctor to leave this sample, or you can order a home testing kit. The kit comes to your home, and you mail the sample back to the laboratory, which gives you your results online. If any type of infection or other abnormal result is found, then you’ll be able to connect with a healthcare professional, so you can be prescribed the right treatment.
Belyayeva M, Jeong JM. Acute Pyelonephritis. https://www.ncbi.nlm.nih.gov/books/NBK519537/. Accessed 18 June 2022.
Dawkins JC, Fletcher HM, et al, Acute Pyelonephritis in Pregnancy: A Retrospective Descriptive Hospital Based-Study. ISRN Obstet Gynecol. 2012; 2012: 519321. doi: 10.5402/2012/519321
Kidney infection. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/kidney-infection/diagnosis-treatment/drc-20353393. Accessed 18 June 2022.
Kidney infection. National Health Service. https://www.nhs.uk/conditions/kidney-infection/. Accessed 18 June 2022.
Kidney Infection (Pyelonephritis). National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-infection-pyelonephritis. Accessed 18 June 2022.