Overview
A urinary tract infection (UTI) occurs when bacteria, most often Escherichia coli, enter and infect any part of the urinary system, including the bladder, urethra, ureters, or kidneys.
Disease Summary
- Category
- Infectious Disease
- Cause
- Bacteria, most commonly Escherichia coli, entering the urinary tract
- Transmission
- Not typically spread person to person; usually results from bacteria near the body entering the urinary tract
- Body System
- Urinary System
- Preventable
- Yes
- Curable
- Yes
Symptoms
Common Symptoms
Most people with a urinary tract infection experience one or more of the following symptoms.
Burning During Urination
A painful or burning sensation while urinating is one of the most common symptoms.
Frequent Urination
A frequent urge to urinate, even when little urine is passed.
Cloudy or Strong-smelling Urine
Urine may appear cloudy or have an unusually strong odour.
Lower Abdominal Pain
Discomfort or pressure in the lower abdomen or pelvic area.
Danger Signs
Seek urgent medical attention if any of the following symptoms develop.
High Fever with Chills
May indicate the infection has spread to the kidneys and requires prompt evaluation.
Flank or Back Pain
Pain in the side or back can signal a kidney infection.
Blood in Urine
Visible blood in the urine should be evaluated promptly.
Confusion
Sudden confusion, especially in older adults, can be a sign of a severe infection or sepsis.
Diagnosis
Clinical Assessment
Diagnosis begins with reviewing symptoms and a brief physical examination.
Urinalysis
A urine sample is checked for white blood cells, nitrites, and other markers of infection.
Urine Culture
Growing bacteria from a urine sample confirms the diagnosis and identifies the best antibiotic to use.
Laboratory Tests
Urinalysis
Checks for white blood cells, nitrites, and other markers of infection in a urine sample.
Urine Culture
Identifies the specific bacteria causing the infection and guides antibiotic choice.
Urine Microscopy
Detects white blood cells, red blood cells, and bacteria under direct examination.
Complete Blood Count (CBC)
Used when a kidney infection or more serious illness is suspected.
Treatment
Antibiotics
Most UTIs are treated with a short course of antibiotics chosen based on local resistance patterns and infection severity.
Pain Relief and Hydration
Drinking plenty of fluids and using pain relief medication can ease discomfort while antibiotics take effect.
Prevention
Stay well hydrated
Drinking enough water helps flush bacteria out of the urinary tract.
Urinate regularly and after sex
Avoiding delays in urination and emptying the bladder after sexual activity can reduce bacterial buildup.
Wipe from front to back
This habit after using the toilet helps prevent bacteria from spreading to the urinary opening.
Avoid unnecessary catheter use
Limiting the use of urinary catheters, and ensuring proper care when they are needed, lowers infection risk.
Risk Factors
High Risk
These factors substantially increase the likelihood of developing a urinary tract infection.
- Female anatomy, including a shorter urethra
- Sexual activity
- Urinary catheter use
Increased Risk
These factors are associated with a moderately higher risk of infection.
- Diabetes
- Pregnancy
- Structural abnormalities of the urinary tract
Additional Contributing Factors
Other factors linked with an increased likelihood of infection.
- Menopause
- History of previous urinary tract infections
- Reduced immune function
Complications
Kidney Infection (Pyelonephritis)
An untreated bladder infection can spread upward to the kidneys, causing more severe illness.
Recurrent Infections
Some people experience repeated UTIs, which may require further evaluation or preventive antibiotics.
Sepsis
In rare cases, a severe UTI can lead to a bloodstream infection, which is a medical emergency.
When to Seek Medical Care
Fever and Flank Pain
May indicate the infection has spread to the kidneys and needs urgent evaluation.
Blood in Urine
Should be assessed by a healthcare provider, especially if it persists.
Symptoms Not Improving on Antibiotics
May indicate resistant bacteria or a different diagnosis.
Confusion in Older Adults
Can be a sign of a severe UTI or sepsis and requires prompt medical attention.
Prognosis
Excellent with Prompt Treatment
Most uncomplicated UTIs resolve completely within a few days of starting antibiotics.
Good with Monitoring for Recurrence
People with recurrent UTIs often do well with preventive strategies and closer follow-up.
Serious if Untreated
Delayed treatment increases the risk of kidney infection and, rarely, sepsis.
Differential Diagnosis
Vaginitis
Can cause similar urinary discomfort but involves vaginal rather than urinary tract infection.
Sexually Transmitted Infections
Can cause burning with urination and pelvic discomfort resembling a UTI.
Interstitial Cystitis
A chronic bladder condition causing pain and urinary frequency without a bacterial infection.
Kidney Stones
Can cause flank pain and blood in urine similar to a kidney infection.
References
Centers for Disease Control and Prevention (CDC)
CDC clinical overview of urinary tract infection types, diagnosis, and treatment.
Mayo Clinic
Patient-focused guidance on diagnosing and treating urinary tract infections.
NCBI Bookshelf (StatPearls)
Clinical reference on the diagnosis and management of uncomplicated urinary tract infections.
Frequently Asked Questions
Can a UTI go away without antibiotics?
Some mild cases may resolve on their own, but most UTIs need antibiotics to fully clear the infection and prevent it from spreading to the kidneys.
Are UTIs contagious?
No. UTIs are not spread from person to person like a cold or flu; they develop when bacteria already present in or near the body enter the urinary tract.
Can men get UTIs?
Yes, though they are less common in men than women due to anatomical differences.
Why do some people get UTIs repeatedly?
Certain anatomical, hormonal, or health factors can make some people more prone to recurrent infections, and a healthcare provider can help identify strategies to reduce them.