Why are women affected more often?
The female urethra is shorter and its opening is close to the anus. Bacteria therefore have a shorter distance to travel to reach the bladder.2,3
Men and children can also get a urinary tract infection.2
Health education · InfectionsCare and treatments
Urinary tract infection: understanding the causes, symptoms and complications
Why does a urinary tract infection occur? How can you recognize the symptoms? And when should you seek care quickly?
A urinary tract infection occurs when bacteria infect part of the urinary system. It most often affects the bladder, but it can also reach the kidneys.6,2 Symptoms and severity vary depending on where the infection is and on the person’s health.
The urinary system
What is a urinary tract infection?
The urinary system has four parts. An infection can affect any of them.
The urinary system includes:
- The kidneys, which filter the blood and make urine.
- The ureters, which carry urine from the kidneys to the bladder.
- The bladder, which stores urine.
- The urethra, which carries urine out of the body.
Two forms of infection are commonly distinguished:
| Infection | Part affected | Main signs |
|---|---|---|
| Cystitis | Bladder | Burning when urinating, frequent or urgent need to urinate, discomfort in the lower abdomen.6 |
| Pyelonephritis | One or both kidneys | Fever, chills, pain in the back or side, sometimes nausea and vomiting.4 |
A kidney infection is more serious than an infection limited to the bladder and needs prompt assessment.2,1
Causes
What are the causes?
Most urinary tract infections are caused by bacteria.6 Escherichia coli, often called E. coli, is the main bacterium involved.3,4
These bacteria can come from the bowel or the area around the anus, enter the urethra and travel up to the bladder. They can then multiply there and cause an infection.2
Is it a sexually transmitted infection?
A urinary tract infection is generally not passed on sexually: it is not an STI.3 However, sexual activity can make it easier for bacteria to move toward the urethra.2
Some STIs can also cause burning when urinating.5 Discharge, genital symptoms or a recent sexual exposure can therefore point the assessment toward other causes.1
Risk factors
What factors increase the risk?
These factors do not automatically lead to an infection, but they can make one more likely.
The risk may be higher with:2,5
- previous urinary tract infections;
- sexual activity;
- changes related to menopause;
- use of spermicides or a diaphragm;
- difficulty emptying the bladder completely;
- something blocking the flow of urine, such as a stone or an enlarged prostate;
- a urinary catheter;
- diabetes or a weakened immune system.
Symptoms
How to recognize the symptoms?
Symptoms must be interpreted together.
The appearance or smell of urine alone is not enough to confirm the diagnosis.4
Consequences
What can the consequences be?
A bladder infection can disrupt sleep, activities and day-to-day comfort.
Most bladder infections that are properly managed do not cause complications.2 An infection can, however, travel up to the kidneys. In some serious situations, it can lead to kidney damage or sepsis, a severe reaction of the body to an infection that can be life-threatening.5
These complications are not the usual course of a simple cystitis, but they explain why it matters to recognize the signs that things are getting worse.
When to seek care
When should you seek care quickly?
Burning when urinating, frequent urges or persistent pain are reasons to see a health professional.
According to Santé Québec, also see a professional if you have, among other things:1
- a yellow discharge from the vagina or penis;
- difficulty urinating, or a feeling that your bladder is not emptying, for more than 24 hours;
- burning or discomfort that persists despite home care;
- symptoms still present after 48 hours of antibiotics;
- fever in a person aged 75 or older who has difficulty doing one or two usual activities.
When should you go to the hospital right away?
According to Santé Québec, go to the hospital without waiting if you have, among other things:1
- fever with back pain;
- nausea and vomiting;
- severe pain that does not go away;
- inability to urinate;
- visible blood in the urine;
- difficulty urinating after a blow, injury or fall involving the genital area.
Fever in a pregnant person, in a person with a weakened immune system or in a baby under three months old also needs assessment without delay.1
For guidance based on your symptoms, call Info-Santé at 811, option 1.1 In an emergency, call 911.
Diagnosis
How is a urinary tract infection confirmed?
The assessment is based on symptoms, medical history, risk factors and, when needed, a physical exam and tests.
Urinalysis
It looks for different elements that can support or reduce the suspicion of infection. It must be interpreted together with the symptoms.
Urine culture
It looks for a bacterium and can help choose an appropriate antibiotic.4
A urinalysis or culture is not needed in every situation.4 The choice depends in particular on the clinical picture, the risk of complications and the person’s history.
Does bacteria in the urine always mean an infection that needs treatment?
No. Bacteria can be present without symptoms: this is called asymptomatic bacteriuria.
It generally does not require an antibiotic. There are exceptions, however, notably pregnancy and certain urological procedures.7
Treatment
How is a urinary tract infection treated?
An antibiotic may be indicated to treat a bacterial infection.10 The choice of medication and the length of treatment depend in particular on the clinical situation, allergies and the results available.
Burning when urinating that is due to another cause may need a different treatment.
Prevention
Can you reduce the risk of recurrence?
Stay hydrated
Drink enough fluids, following any medical restriction.
Don’t hold it in
Go to the bathroom when you feel the need.
Empty your bladder
Take the time to empty your bladder completely.
Wipe front to back
After a bowel movement, to avoid bringing bacteria toward the urethra.
Avoid vaginal douching
It is among the practices to avoid to help prevent infections.
Review spermicide use
Discuss it with a professional when infections keep coming back.10
Repeated infections deserve an assessment to look for the factors that promote them and to discuss suitable prevention. According to INESSS, this applies in particular after more than 2 episodes in 6 months or more than 3 episodes in a year.8
What about cranberry products?
They do not treat a urinary tract infection that is already present: nothing shows that they do.2 They should therefore not replace an assessment or an indicated treatment.
For prevention, the evidence is mixed. Santé Québec and INESSS state that their preventive effect has not been clearly demonstrated.1,8 A Cochrane review published in 2023 concludes that they may reduce the risk of infection in some people, such as women with repeated infections, but not in others, such as pregnant people.11 Talk to a professional before taking them.
When to consult at the Clinique IPS du Palais?
Urinary tract infections are among the common health problems the clinic can assess, according to the applicable clinical criteria. A nurse practitioner can assess your symptoms, order the necessary tests and suggest suitable treatment, within the limits of her scope of practice.
Urinary tract infection is also one of the examples of reasons for a teleconsultation at the clinic. If you have warning signs, go to the hospital without waiting.
Sources
- Santé Québec. Infection urinaire ou douleur en urinant (health advice, based on the nursing self-care education guides of Santé Québec – Capitale-Nationale; in French). Updated October 8, 2026, accessed October 29, 2026. sante.quebec
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK, National Institutes of Health). Definition & Facts of Bladder Infection in Adults. Reviewed April 2024, accessed October 29, 2026. niddk.nih.gov
- La Fondation du rein (Kidney Foundation). Les infections des voies urinaires (leaflet, in French). 2020, accessed October 29, 2026. rein.ca
- CIUSSS de l’Estrie – CHUS (Nadeau E.). Cystite et pyélonéphrite aiguë, practice guide GPR-IF-011 (in French). Version of February 14, 2024, accessed October 29, 2026. santeestrie.qc.ca
- Mayo Clinic. Urinary tract infection (UTI) – Symptoms and causes. Updated September 26, 2025, accessed October 29, 2026. mayoclinic.org
- NIDDK. Symptoms & Causes of Bladder Infection in Adults. Reviewed April 2024, accessed October 29, 2026. niddk.nih.gov
- CIUSSS du Saguenay–Lac-Saint-Jean. Guide d’antibiothérapie : infection urinaire chez l’adulte (in French). December 2024, accessed October 29, 2026. santesaglac.gouv.qc.ca
- Institut national d’excellence en santé et en services sociaux (INESSS). Infection urinaire : fiche à l’intention des personnes atteintes (in French). March 2024, accessed October 29, 2026. inesss.qc.ca
- Health Canada. Ce que vous devez savoir au sujet des médicaments antimicrobiens, y compris les antibiotiques (French version of the fact sheet). Modified December 17, 2024, accessed October 29, 2026. canada.ca
- NIDDK. Treatment of Bladder Infection in Adults. Reviewed April 2024, accessed October 29, 2026. niddk.nih.gov
- Williams G, Stothart CI, Hahn D, Stephens JH, Craig JC, Hodson EM. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews, November 10, 2023 (CD001321.pub7), accessed October 29, 2026. cochrane.org
This information is provided for informational purposes and does not replace an assessment by a health professional. Published October 29, 2026.