Urinary tract infections in women: symptoms, diagnosis and treatment
In brief
A urinary tract infection (UTI) in women is most often cystitis, an infection of the bladder that causes burning and frequent, urgent need to pass urine, without fever. Fever, shivering or pain in the back on one side suggest pyelonephritis, a kidney infection that must be treated without delay. Diagnosis is based on symptoms, a urine dipstick test and, depending on the case, a urine culture. Under French guidelines, uncomplicated cystitis is treated first-line with a single-dose antibiotic, fosfomycin trometamol.
What is the difference between cystitis and a kidney infection?
Urinary tract infections are caused by bacteria, most often Escherichia coli, from the bowel, which travel up the urethra to the bladder. Because women have a short urethra, these infections are common. They also affect women being treated for pelvic floor problems or who have had gynaecological surgery, particularly after a urinary catheter.
| Cystitis | Pyelonephritis (kidney infection) | |
|---|---|---|
| Organ affected | Bladder | Kidney |
| Symptoms | Burning when passing urine, frequent and urgent need to go, small amounts, pain above the pubic bone, cloudy or blood-stained urine | Sometimes signs of cystitis, plus fever, shivering, pain in the back or flank on one side, nausea or vomiting |
| Fever | No | Yes, in most cases |
| Seriousness | Mild | Needs prompt treatment; risk of complications |
Burning when passing urine is not always a urinary infection. Thrush, vaginal dryness or a sexually transmitted infection can cause similar symptoms. If the burning comes with unusual vaginal discharge or itching, or starts after a new partner, a gynaecological examination is useful: see our article on vaginal discharge.
What makes urinary infections more likely
- sex and some spermicides;
- not drinking enough and going too long between visits to the toilet;
- constipation;
- pregnancy and the menopause;
- diabetes and abnormalities of the urinary tract.
How is a urinary tract infection diagnosed?
- Simple cystitis: in a woman with no risk factors, symptoms and a urine dipstick test are enough. A negative dipstick (no white blood cells and no nitrites) makes infection unlikely.
- Urine culture (in France, ECBU): it identifies the bacterium and tests which antibiotics it responds to. It is requested for cystitis at risk of complications, recurrence, treatment failure, kidney infection and during pregnancy.
- Blood tests and ultrasound of the kidneys and bladder for a kidney infection, depending on how serious it is.
How do I collect a urine sample correctly?
- Wash your hands, then wash the vulva with water and mild soap, from front to back.
- Hold the outer lips apart, pass the first part of the urine into the toilet, then collect the middle part of the stream in the sterile container.
- Take the container to the laboratory quickly; otherwise, keep it in the fridge as instructed by the laboratory.
How is cystitis treated?
Simple cystitis is treated with a short course of antibiotic, chosen according to the French guidelines of the French-Language Society of Infectious Diseases (SPILF). A single dose of fosfomycin-trometamol is the first-line treatment; pivmecillinam for a few days is an alternative. Your doctor tailors the choice to your history, allergies and the urine culture if one was done.
Symptoms can persist for two to three days after effective treatment. If they last longer, or come back quickly, see your doctor again: a urine culture will be requested.
While waiting for the treatment to work, drink regularly and pass urine without holding on. A simple painkiller such as paracetamol can ease the burning.
Do not take “leftover” antibiotics from a previous course: self-medicating encourages bacterial resistance and can mask a more serious infection.
How is a kidney infection (pyelonephritis) treated?
A kidney infection requires a urine culture before any antibiotic, followed by tailored treatment, usually for 7 to 10 days. Most women are treated at home. Hospital admission is needed if there are signs of severity, vomiting that prevents you from taking tablets, pregnancy, or a blockage in the urinary tract.
Some situations carry a risk of a complicated infection: pregnancy, an abnormality or stone in the urinary tract, severe kidney failure, weakened immunity, a urinary catheter, or frailty linked to age. A poorly treated kidney infection can lead to a kidney abscess or a bloodstream infection (sepsis).
Why does cystitis keep coming back?
Cystitis is described as recurrent from 4 episodes in 12 months, according to the definition used by the SPILF. Initial tests include a urine culture during an episode and looking for a contributing factor: sex, constipation, not drinking enough, the menopause, prolapse, incomplete bladder emptying. An ultrasound of the bladder and kidneys, with measurement of the urine left after passing urine, is requested depending on the situation. A CT urogram or cystoscopy is only offered in specific cases.
Prevention
- Drink enough, at least 1.5 litres a day unless advised otherwise.
- Pass urine regularly, without holding on, and after sex.
- Treat constipation.
- Avoid harsh intimate washes and vaginal douching.
- After the menopause, vaginal oestrogen treatment can reduce recurrences.
- Cranberry products may reduce the risk of a new episode in women with repeated infections, according to a 2023 Cochrane review.
After the menopause
Falling oestrogen levels change the vaginal flora and the lining of the urethra, which makes infections more likely. Prolapse or a bladder that does not empty properly can also play a part. A gynaecological examination is therefore part of the assessment of recurrent cystitis in post-menopausal women.
If these measures are not enough, preventive antibiotic treatment can be discussed. Associated leaks or urinary discomfort may call for urodynamic tests.
What precautions are needed for a UTI during pregnancy?
During pregnancy, progesterone relaxes the urinary tract and the womb presses on the bladder and ureters. Urinary infections are therefore more common, and asymptomatic bacteriuria (bacteria in the urine without symptoms) can develop into a kidney infection, which carries a risk of premature birth.
- Screening: in France, a urine dipstick test is done every month from the 4th month; in women at risk (previous infections, diabetes, urinary abnormality), a urine culture is requested instead.
- Treatment: any confirmed bacteriuria is treated, even without symptoms, with an antibiotic that is safe in pregnancy and suited to the urine culture.
- Follow-up: a urine culture is repeated 8 to 10 days after the end of treatment, then every month until the birth.
See also our article on care during a normal pregnancy.
When is a urinary tract infection an emergency?
See a doctor the same day, or call 15 (SAMU, the French emergency medical service) or 112 in France, or your local emergency number, if your condition is worrying, if you have:
- fever (38°C or above), shivering;
- pain in the back or side;
- vomiting that stops you drinking or taking treatment;
- feeling faint, confusion, rapid breathing;
- urinary symptoms during pregnancy: contact your maternity unit;
- no improvement 72 hours after starting an antibiotic.
For a consultation at the practice, book on Doctolib or call 01 43 79 59 79; a video consultation is also possible. In a life-threatening emergency, call 15 or 112.
Frequently asked questions
Can cystitis clear up without antibiotics?
Some mild cases of cystitis clear up on their own, but antibiotics shorten symptoms and reduce the risk of the kidney becoming infected. Talk to your doctor, especially if you have fever or back pain.
Does sex make cystitis more likely?
Yes, it helps bacteria travel up to the bladder. Passing urine after sex and drinking enough help limit this risk.
Do I need a follow-up urine test after simple cystitis?
No, if your symptoms go away. A urine culture is, however, needed if symptoms persist, come back quickly or occur during pregnancy.
Is cranberry juice enough to prevent urinary infections?
Cranberry products may reduce recurrences in some women, but they do not treat an active infection and are no substitute for medical advice.
References
- Caron F, et al. Practice guidelines for the management of adult community-acquired urinary tract infections (SPILF). Médecine et Maladies Infectieuses, 2018. doi:10.1016/j.medmal.2018.03.005 — PMID 29759852
- HAS, SPILF. Choix et durées d’antibiothérapies : cystite aiguë simple, à risque de complication ou récidivante, de la femme [Antibiotic choice and duration: acute uncomplicated, complicated or recurrent cystitis in women]. Memo sheet, 2016, updated 2024. has-sante.fr
- Williams G, et al. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews, 2023. doi:10.1002/14651858.CD001321.pub7 — PMID 37947276
Dr Olivier KadochObstetrician-gynaecologist and gynaecological surgeon in Paris (16th and 5th arrondissements). Former chef de clinique-assistant (senior registrar) at the Paris public hospitals (AP-HP); individually accredited by the French National Authority for Health (HAS). RPPS 10003957809. Background and practice locations
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