Urinary tract infection (UTI) is one of the most common reasons for a consultation, especially in women. Most of the time it is a passing nuisance that is easy to treat; but it is worth knowing how to recognise when a urinary infection stops being trivial and can affect the kidney. That distinction is the key to this article.
What a urinary infection is
We speak of a UTI when microorganisms — almost always bacteria, led by Escherichia coli — colonise and infect some part of the urinary tract. Depending on where they settle, we distinguish two very different scenarios:
- Cystitis (lower tract): affects the bladder and urethra. It causes burning when passing urine, urgency, frequent urination in small amounts, and sometimes blood in the urine. It usually occurs without fever.
- Pyelonephritis (upper tract): the infection ascends and reaches the kidney. Here we see high fever, chills, pain in the lower back or flank, nausea and a general feeling of illness. This is a more serious situation.
The practical rule is simple: cystitis is bothersome; pyelonephritis also brings fever and flank pain. Fever changes things.
Warning signs
You should seek care promptly if you develop:
- Fever, chills or intense pain in the back or flank.
- Vomiting that prevents you from staying hydrated or taking medication.
- Heavy blood in the urine.
- Symptoms that don't improve within 48-72 hours of treatment.
- Infections that keep coming back (several episodes a year).
When should the nephrologist step in?
Most cases of cystitis are handled by the family doctor. Assessment by Nephrology or Urology makes sense in specific situations: recurrent urinary infections, pyelonephritis, the presence of stones or anatomical abnormalities of the urinary tract, patients with a single kidney or a transplant, people with chronic kidney disease or diabetes, and men with a UTI (who always deserve a closer look). In these cases, an infection may damage kidney tissue or be the tip of the iceberg of another problem.
Prevention: small habits that help
- Hydration: drinking enough water helps "flush" the urinary tract.
- Don't hold in urine and empty the bladder well, including after sexual intercourse.
- Proper hygiene, wiping front to back in women.
- Address contributing factors: constipation, poor diabetes control or the use of certain devices.
An important nuance: not every bacterium in the urine is an infection. In people without symptoms — except in pregnancy or before certain procedures — so-called asymptomatic bacteriuria is usually not treated, to avoid unnecessary antibiotics and resistance. Diagnosing well is as important as treating.