Recurrent Urinary Tract Infection: Causes and Prevention
What is a recurrent urinary tract infection, why is it common in women and how can it be prevented? Symptoms, diagnosis, menopause, pregnancy and when to see a doctor.
Burning when you urinate, going to the toilet often, a feeling of pressure in the lower abdomen... If it comes back within months of being treated, this may be a "recurrent urinary tract infection." Most women have at least one urinary tract infection in their lifetime; for some, it turns into a vicious circle. This article explains what a recurrent urinary tract infection is, why it is so common in women, when treatment is needed and how it can be prevented. For its link with intercourse, you can also read our article on urinating after intercourse.
What Is a Recurrent Urinary Tract Infection?
A urinary tract infection (UTI) happens when bacteria enter the urinary tract and multiply. An infection of the bladder (the urine sac) is called cystitis. A recurrent UTI means infections confirmed by a culture (growing the bacteria from the urine) that happen at this frequency:
- 2 or more attacks in the past 6 months
- 3 or more attacks in the past 12 months
About 50-60% of women have at least one UTI in their lifetime. In women who have not reached menopause, about 20-30% of those who have a first attack have another within 3-6 months. A recurrent pattern develops in about 5% of women.
What Are the Symptoms?
Bladder infection (cystitis):
- Burning or stinging when urinating
- A need to go to the toilet often and a sudden feeling of urgency
- Pressure, fullness and pain in the lower abdomen and groin
- Cloudy, foul-smelling and sometimes bloody urine
Kidney infection (pyelonephritis): When the infection climbs from the bladder to the kidney, in addition to the above, high fever (above 38 degrees), severe chills, back and flank pain, nausea, vomiting and weakness are seen. This picture is more serious and should be assessed the same day.
Why Is It Common in Women?
In women the urethra (the tube that carries urine out) is only about 4 cm long, much shorter than in men, and its opening is very close to the vagina and the anus. Bacteria from the bowel, especially E. coli, can easily climb up the urethra to the bladder.
Risk factors before menopause:
- Frequent intercourse (bacteria can be carried up the urethra during intercourse)
- Use of spermicide (a sperm-killing product) or a diaphragm (a birth control device that covers the cervix); these disturb the protective bacterial flora of the vagina
- A new sexual partner
- Having a first UTI at a younger age
- A history of UTIs in the mother
Risk factors after menopause:
- Estrogen deficiency: The inner lining of the vagina and urethra thins, protective bacteria (lactobacilli) decrease and the acidity of the vagina falls. This makes it easier for harmful bacteria to multiply. For details, see our article on genitourinary syndrome of menopause.
- Urine left in the bladder after voiding: Pelvic organ prolapse, narrowing of the urethra or an age-related bladder muscle that cannot empty fully may be the causes.
- Urinary leakage and inadequate genital hygiene. For urinary leakage, see our urinary incontinence page.
Risk factors at any age: Diabetes, pregnancy, excess weight, kidney or bladder stones and use of a urinary catheter.
How Is It Diagnosed?
- Urine test: White blood cells (infection cells), nitrite and bacteria in the urine support the diagnosis. In a first attack of cystitis with typical complaints, this test and the symptoms are often enough to start treatment.
- Urine culture: A test that grows the bacteria from the urine and shows which antibiotic works. It is always requested in recurrent infections, when there is no response to treatment within 48 hours, when a kidney infection is suspected, in pregnant women and in complicated infections.
Bacteria in the urine of a woman with no complaints: This is called asymptomatic bacteriuria (bacteria without symptoms). In women who are not pregnant, before or after menopause, in people with diabetes and in older adults it is not treated; unnecessary antibiotics increase the resistance problem. Screening and treatment are done only in these situations:
- Pregnancy
- Before a urology operation or procedure in which bleeding of the inner lining (mucosa) is expected
- Bacteriuria that continues 48 hours after a catheter is removed
How Can It Be Prevented?
Daily habits:
- Enough fluids: Drinking more supports urine flow and helps wash bacteria out of the bladder.
- Urinating after intercourse: Urinating within the first 15-30 minutes after intimacy helps flush out bacteria pushed into the urethra during intercourse.
- Wiping front to back: After using the toilet, cleaning should be done from front to back so that bowel bacteria are not carried to the urethra.
- Not holding urine: The bladder should be emptied fully at regular intervals.
- Reviewing the birth control method: If spermicide or a diaphragm increases infections, you can move to another method together with your doctor.
These measures are widely recommended, but the level of evidence in studies is moderate. They are simple, first-step habit changes that carry no known harm.
Supportive options:
- Cranberry: Its components make it harder for E. coli to stick to the bladder wall. It has been shown that it may help reduce attacks in women with recurrent infections. However, it does not treat an existing infection and should be seen only as preventive support.
- D-mannose and probiotics (products containing beneficial bacteria): Used to support the flora of the vagina. The evidence in international guidelines is still limited; they are among the complementary options.
What Does Vaginal Estrogen Do After Menopause?
After menopause, when estrogen falls, the inner lining of the vagina and urethra thins and the protective bacteria disappear. Low-dose estrogen applied to the vagina (cream, ring or vaginal tablet) is a treatment with very little passing into the blood. It thickens this lining again and restores the protective bacterial flora and the acidity of the vagina. In studies it has been reported to cut recurrent UTI attacks by more than 90% in women after menopause. The decision to use it is made by the doctor.
Preventive Medicine Approaches Under a Doctor's Supervision
In women who do not get enough response from daily habit changes, the following approaches may be considered according to the urine culture result and under a doctor's supervision:
- A single low dose of a preventive antibiotic every night for 3-6 months
- A single preventive dose of antibiotic only after intercourse
- Starting short treatment when symptoms begin, with a prescription the doctor has given beforehand
Antibiotic resistance: Careless, incomplete or too frequent antibiotic use creates resistance in the bacteria that cause UTIs. That is why in recurrent infections it is important to confirm each attack with a urine culture and choose the medicine according to the culture result. Do not start antibiotics on your own or stop them halfway.
Urinary Tract Infection in Pregnancy
- The hormone progesterone, which rises in pregnancy, relaxes the smooth muscles of the urine channels (ureters), and the growing uterus presses on them. Urine flow slows and infection becomes easier.
- About 2-7% of pregnant women have bacteria in the urine without symptoms. If not treated, 20-40% of these can progress to a serious kidney infection.
- For this reason, a urine culture is taken from every pregnant woman at the first pregnancy visit, and if bacteria grow, they are treated with antibiotics that are safe in pregnancy.
- An untreated UTI raises the risk of preterm birth, a low-birth-weight baby and serious infection in the mother and baby.
When Should You See a Doctor?
- When burning on urination, frequent urination or lower abdominal pain begins: to be examined
- High fever, chills, back or flank pain, nausea and vomiting or visible blood in the urine: the same day
- In pregnancy, with the slightest urinary complaint or fever: without delay, to an obstetrician-gynecologist or the emergency department
- If blood in the urine is seen for the first time and keeps recurring, especially over age 40-50
Frequently Asked Questions
Is a urinary tract infection a sexually transmitted disease?
No. It mostly comes from a person's own bowel bacteria. Intercourse can be a risk factor by making it easier for bacteria to be carried up the urethra.
My symptoms have gone, but the urine culture still shows bacteria. Is treatment needed?
If you have no symptoms, are not pregnant and none of the special situations above apply, treatment is often not needed. The decision belongs to your doctor.
Does cranberry juice treat the infection?
No. Cranberry does not treat an existing infection; in people with recurrent infections it can only be considered as preventive support.