Medically Reviewed on 1/24/2022
Additional symptoms from a UTI
Kidney infections are always caused by a pathogen in your organs. The beginning of a kidney infection may produce back pain, fever, chills, fatigue, loss of appetite, nausea, vomiting and diarrhea.
Your kidneys are a pair of organs located in the middle of your back, just below your ribs. Their primary function is to filter waste from your blood into your bladder for elimination. Kidney infections are caused by pathogens — like certain kinds of bacteria — in one or both of these organs.
How do you know if you have a kidney infection? Symptoms tend to set in suddenly — over just hours or days.
The most common symptoms of an infection include:
- Pain in your lower back, side, or genital regions
- A fever with a temperature possibly as high as 103?
- Loss of appetite, nausea, and vomiting
In most cases, the bacteria that cause your kidney infection originate in your digestive tract. E. coli from your bowels causes between 75% and 90% of all cases of kidney infection. Other pathogens that can cause kidney infections include Enterobacteriaceae other than E. coli and S. saprophyticus.
If you’re experiencing many of the symptoms listed above and have had an untreated urinary tract infection (UTI) for an extended period, then you most likely have a kidney infection. But keep in mind that not all people with a kidney infection have the added symptoms of a UTI.
These additional symptoms include:
- The urgent need to urinate
- Frequent urination that might also be painful
- Urine that’s cloudy, dark, or smells bad
- Blood in your urine
- The feeling that you can’t fully empty your bladder
- Pain in your lower abdomen — the area around your belly
Additional symptoms in younger and older populations
Young children and adults 65 and older may have unusual symptoms from a kidney infection that aren’t seen in other age groups.
Symptoms that are unique to children include:
- Vomiting when feeding or poor feeding
- Growing more slowly than expected
- Jaundice — when your child’s skin and the whites of their eyes take on a yellowish tint
Very young children — under the age of two — might not have any symptoms other than a high fever.
Adults over 65 might not have any of the classic kidney infection symptoms at all. Instead, they might develop symptoms that impair their thought processes, including:
- Jumbled speech
What is chronic kidney disease (CKD)?
It’s important to know the differences between chronic kidney disease (CKD) and kidney infections. But keep in mind that both require medical attention as soon as possible.
The symptoms of kidney infections tend to appear suddenly, but many forms of chronic kidney disease have no initial symptoms. CKD symptoms don’t appear until your kidneys are badly damaged. They can include many of the symptoms of a kidney infection and symptoms that are not common in kidney infections.
Examples of these additional symptoms include:
- Swelling from fluid build-up in your ankles, feet, hands, or face
- Skin rashes and itching
- An ammonia smell in your breath
- A metallic taste in your mouth
- Feeling cold from anemia
- Dizziness and trouble concentrating, regardless of age
Kidney infections are always caused by a pathogen in your organs. CKD can be caused by a large number of underlying conditions. The top two are diabetes and high blood pressure.
Untreated kidney infections — or kidney infections that keep coming back — can scar your organs. Over time this can lead to chronic kidney disease. But antibiotics usually treat kidney infections effectively, so you can prevent your infection from developing into CKD.
When should you see a doctor?
Kidney infections can lead to long-term kidney damage if they’re left untreated, so don’t hesitate to contact your doctor if you believe that you have or your child has a kidney problem.
The best way to know for sure if you have a kidney infection is to get a diagnosis from your doctor. They’ll perform a physical examination of your abdominal and pelvic areas. A clean-catch urine sample typically follows this. You’ll need to follow the instructions carefully so you don’t contaminate this sample.
Also, you should always contact your doctor if you see blood in your urine or experience long-term or severe pain in your tummy, lower back, or genital regions.
Urinary Incontinence in Women: Types, Causes, and Treatments for Bladder Control
Medically Reviewed on 1/24/2022
Johns Hopkins Medicine: “Chronic Kidney Disease,” “Pyelonophritis, Acute, Uncomplicated.”
National Institute of Diabetes and Digestive and Kidney Diseases: “Symptoms and Causes of Kidney Infection (Pyelonephritis).”
National Kidney Foundation: “Infectious Disease and Your Kidneys.”
Nidirect Government Services: “Kidney infection.”