Mar 02, 2026
Urinary tract infections (UTIs) are common, and many people think they affect the bladder or genitals. But did you know that UTIs can affect any part of your urinary system?
Early detection is key and knowing the difference between an upper and lower urinary tract infection can help you spot symptoms sooner and start treatment earlier.
We look at what sets these apart, their causes, symptoms, and when you should contact your doctor.
What are Lower and Upper Urinary Tract Infections?
UTIs can affect any urinary organ, including the kidneys, ureters, bladder, and urethra. 1 They are grouped into two UTI types based on where in the urinary tract the infection occurs. 1
Upper urinary tract infections affect the kidneys and ureters, while lower urinary tract infections involve the bladder and urethra. 1
Upper UTIs are generally more serious because, if left untreated, they can lead to kidney damage. That’s why it's important to see a doctor as soon as you notice symptoms.2
If you struggle with bladder weakness, you are also more prone to UTIs. Which means you should definitely know what causes a UTI and the symptoms to get early treatment!
What Causes a Lower UTI vs. Upper UTI?
Most urinary tract infections, whether lower or upper UTIs, begin when microorganisms, like bacteria, fungi, or viruses, enter the urethra and start to grow.1,3,4
They often start in the lower urinary tract, and if left untreated, can travel upward to affect the kidneys and ureters.5
Let’s take a closer look at each of these microorganisms:
Bacteria
Escherichia coli (AKA E. coli) is the most common cause of uncomplicated UTIs.1 These bacteria normally live in the anus, but they can sometimes travel from the area around the anus into the urethra.1
From there, they can move into the bladder and, in some cases, continue upward to the kidneys.1 This movement is what can lead to infections like cystitis in the bladder and pyelonephritis in the kidneys.1
Viruses
Viral UTIs are rare, but they can occur in people with weak immune systems or after medical treatments like organ transplants.3
Viruses like adenovirus, human papillomavirus (HPV), cytomegalovirus (CMV), and herpes simplex can cause these infections.3 When they do, the virus could affect the prostate, leading to prostatitis, or the urethra, causing urethritis.3
Parasites
While parasitic UTIs are rare in the US, they can occur in certain geographic regions or after you’ve returned from your travels.
Schistosoma is a tiny parasite found in freshwater in some parts of Africa and the Middle East. One type, S. haematobium, can infect the urinary tract, sometimes causing blood in the urine. Travelers who swim or work in contaminated water can be exposed to this parasite.11
Fungi
Fungal UTIs are usually caused by Candida albicans.4 These fungi naturally live in various parts of the body, but an imbalance allows them to multiply and trigger an infection in the urinary tract.4
Imbalances can happen for several reasons, such as the use of catheters, diabetes, or if you have a weak immune system, which can make it easier for the fungi to grow.4
Who’s Most at Risk for a Urinary Tract Infection?
Both upper and lower UTIs can affect anyone, but certain people are more likely to develop them:
- People with kidney stones or an enlarged prostate1
- Menopausal women1
- People with weakened immune systems1
- Long-term catheter users1
- Pregnant women1
- People with certain health conditions, such as diabetes1
- Older adults7
What are the Symptoms of a Lower UTI vs. Upper UTI?
UTI symptoms often depend on which part of the urinary tract is affected.6 Infections in the upper urinary tract tend to cause more severe symptoms that can affect the whole body, while lower UTIs usually stay focused around the bladder and urethra.6
Upper UTI:
Upper UTI symptoms develop quickly.1 It’s important to seek medical care as soon as symptoms appear, because these infections can become serious.6
Common upper urinary tract infection symptoms may include:
- Fever higher than 101°F1
- Chills1
- Nausea1
- Vomiting1
- Back or side pain1
- A general feeling of being unwell6
In older adults, upper urinary tract infections might show up differently. You may notice:1
- Confusion
- Extreme tiredness
- Poor appetite
- Fever or unusually low body temperature
Lower UTI:
With a lower urinary tract infection, you might notice these early signs:6
- A burning sensation while peeing
- Feeling the need to pee more often than usual
- Cloudy or strong-smelling pee
- Sudden urges to pee that are hard to control
- Occasional bladder leaks or incontinence
- Discomfort or pressure in the lower belly
How is a Lower or Upper UTI Diagnosed?
Before a UTI diagnosis, your doctor will usually ask you questions about:1
- Your current symptoms
- Past health conditions
- Previous surgeries
- Medications you take
- Lifestyle habits
Common tests he may do include:
- Urinalysis: To check for signs of infection in your urine1
- Urine culture: This helps guide safe and effective treatment1
- Blood tests: Identify complicated UTIs, such as a kidney infection1
- Pelvic exam: Ensures another condition isn’t causing your symptoms1
- Imaging tests: These are done when infections are complicated UTIs, recurrent, or affecting the kidneys8
Your doctor combines all the information, the physical findings and medical test results to confirm a diagnosis.1
How is a Lower and Upper UTI Treated?
Antibiotics are usually the first choice for treating both lower and upper UTIs.1 The type, route, and duration of treatment depend on factors like the type of UTI, your age, and your gender.1 Doctors may also recommend intravenous therapy for upper UTIs.1
Antibiotics might make you feel better before you finish your full course,1 but it’s important to complete the course to ensure that the infection is completely gone.1
You can also try a few simple ways to ease your symptoms while your antibiotics start working:1
- Staying well-hydrated
- Avoiding bladder irritants like spicy food, coffee, and alcohol
- Using a hot water bottle for comfort
- Drinking cranberry juice
If you’re caring for someone prone to UTIs or who already has a UTI, read our article on UTI prevention and treatment for caregivers.
Are Complications Possible?
If UTIs are left untreated, infections may come back, and complications could occur, especially with upper UTIs.1 These complications can include:
- Kidney damage1
- Sepsis9
- Pregnancy-related risks, such as preterm labor9
How to Prevent UTIs
UTIs can be uncomfortable, but simple daily habits can help lower your risk. Here are some prevention tips:
- Wiping from front to back after using the toilet1
- Changing incontinence pads regularly2
- Staying well-hydrated1
- Peeing after sex1
To help prevent recurrent UTIs, follow your doctor’s instructions, including finishing your full course of antibiotics.1
If you are experiencing leaks, drips, or dribbles during a bout of urinary tract infection, we’ve got you. Find your fit and explore our range of related incontinence products, designed with your comfort, skincare, and confidence in mind.
FAQs
How will I know if a UTI is upper or lower?
Lower UTIs usually affect your urinary habits, like how often you pee.6 Upper UTIs tend to cause symptoms that affect the whole body, like fever or back pain.6
It's confusing to tell the difference based on symptoms alone. Your doctors are trained to diagnose your UTI through medical tests and to determine the best treatment.
How do I know if I have an uncomplicated or complicated UTI?
Uncomplicated UTIs usually affect the bladder or urethra in people who are otherwise healthy.10 Complicated UTIs occur when there are factors that make infections harder to treat or more likely to return, like catheter use.10
References
1. R. Balentine J. Urinary Tract Infection Treatment, UTI Causes & Home Remedies [Internet]. MedicineNet. Available from: https://www.medicinenet.com/urinary_tract_infection/article.htm
2. Age UK. UTI information and support | Age UK [Internet]. Ageuk.org.uk. 2018. Available from: https://www.ageuk.org.uk/information-advice/health-wellbeing/conditions-illnesses/urinary-tract-infections-utis/
3. Park S, Kim ET, Huh JS. Virus in the Urine of Healthy People and Patients with Infectious Diseases. Urogenital Tract Infection. 2021 Aug 31;16(2):44–8.
4. Behzadi P, Behzadi E, Ranjbar R. Urinary tract infections and Candida albicans. Central European Journal of Urology. 2015;68(1).
5. Mayo Clinic. Urinary tract infection (UTI) - symptoms and causes [Internet]. Mayo Clinic. 2022. Available from: https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447
6. Urology Specialists. Symptoms of a UTI | Urology Specialists [Internet]. Urology Specialists. 2023. Available from: https://urologyspecialistsnc.com/24-symptoms-uti/
7. Centers for Disease Control and Prevention. Urinary tract infection basics [Internet]. Urinary Tract Infection. 2024. Available from: https://www.cdc.gov/uti/about/index.html
8. El-Ghar MA, Farg H, Sharaf DE, El-Diasty T. CT and MRI in Urinary Tract Infections: A Spectrum of Different Imaging Findings. Medicina. 2021 Jan 1;57(1):32.
9. Whalen R. Understanding UTI Complications: Risks, Prevention [Internet]. urologyconferences.com. 2025. Available from: https://urologyconferences.com/understanding-uti-complications/
10. McIntosh J. What is the difference between a complicated and uncomplicated UTI? [Internet]. Medicalnewstoday.com. Medical News Today; 2024. Available from: https://www.medicalnewstoday.com/articles/complicated-vs-uncomplicated-uti#uncomplicated-uti
11. Schistosomiasis. Cleveland Clinic. 2025. Available at: https://my.clevelandclinic.org/health/diseases/22631-schistosomiasis
