Urinary tract infection: symptoms and when to seek care
Cystitis commonly causes burning and a frequent urge to urinate. Fever, chills and lower back pain may indicate a kidney infection and require urgent assessment.
Burning when passing urine, urgency and frequent trips to the toilet are common symptoms of a bladder infection, called cystitis. Fever, chills, back pain or vomiting may indicate kidney involvement and require urgent in-person care. Strong-smelling urine alone does not confirm an infection. Assessment determines whether tests are needed and which treatment is appropriate; during pregnancy, seek assessment without delay if urinary symptoms develop.
Recognising the problem
Which symptoms may indicate a urinary tract infection?
With cystitis, the urge to urinate may return soon after using the toilet, even when little urine is passed.
There may also be burning, pressure in the lower abdomen and blood in the urine. These symptoms guide the consultation, but cannot on their own identify the bacteria or the appropriate antibiotic. Genital discharge or itching may suggest other causes, such as vulvovaginitis or sexually transmitted infections.
A change in the smell or colour of urine without urinary symptoms is not enough to diagnose an infection or start antibiotics. The doctor assesses the whole picture: what has changed, when it began, associated symptoms and your history.
Urinary tract infection is a broad term. Cystitis affects the bladder; pyelonephritis affects the kidneys. Fever, chills, lower back pain and feeling unwell change the urgency of assessment.
Sources: Joint recommendations from SBI, FEBRASGO, SBU and SBPC/ML (2020); IFF/Fiocruz, material on recurrent UTI in women, pp. 7–10.
When not to wait
Fever, back pain or vomiting require urgent assessment
Urinary symptoms with fever, chills, lower back pain or vomiting require urgent in-person care.
Go to a UPA (urgent care unit) or urgent care service if a kidney infection is suspected or you cannot drink fluids. Visible blood in the urine also needs assessment. Do not wait for a more serious infection to cause every sign at once.
During pregnancy, contact your antenatal team or seek assessment without delay. Men and people with kidney disease, diabetes, reduced immunity or a urinary catheter also need individual assessment: advice for simple cystitis in a non-pregnant woman does not automatically apply to these cases. This article is for adults.
Sources: Brazilian recommendations on UTI; TelessaúdeRS/UFRGS, urinary symptoms in pregnancy; Secretaria Municipal da Saúde de Curitiba, UPA protocol (2024), pp. 1–2; Ministério da Saúde, SAMU 192.
Diagnosis
Is a urine test always necessary?
Not every case of cystitis requires a test to confirm the diagnosis. A urine culture is particularly useful during pregnancy, when a kidney infection is suspected and when episodes recur or treatment fails.
In non-pregnant women without complicating factors and with typical symptoms, clinical assessment may be sufficient. This does not justify self-diagnosis: a healthcare professional needs to confirm that the presentation fits this situation and consider other causes of burning.
A routine urine test looks for changes that help with assessment. A urine culture identifies bacteria and can guide antibiotic choice according to susceptibility. If your doctor requests a sample, confirm when to provide it in relation to starting treatment; do not delay urgent care to arrange a test yourself.
Mention previous infections, recent antibiotic use, allergies, kidney stones or the possibility of pregnancy. Discharge, itching and symptoms after sex also help determine what to investigate.
Sources: Brazilian recommendations, diagnosis and indications for urine culture; IFF/Fiocruz, pp. 16–18.
Avoid self-medication
Antibiotics: why an old prescription may not be suitable
Treatment depends on the site of infection, your history, allergies and the possibility of bacterial resistance.
A prescription that worked for another episode may not be appropriate now. Do not use leftovers or share antibiotics, and follow the prescribed dose and duration. If side effects occur or you have difficulty taking the medicine, speak to the healthcare professional responsible before making changes yourself.
After starting treatment, seek reassessment if there is no improvement within 48 hours. Worsening at any time, fever, lower back pain, vomiting or difficulty drinking fluids require care sooner. The 48-hour period is a guide for reviewing the response to treatment, not advice to delay the first consultation.
If a urine culture result is pending, agree how it will be reviewed. It may show that the antibiotic needs adjusting. Recurrent episodes also deserve investigation and their own plan, rather than repeating old prescriptions.
Sources: Anvisa, correct antibiotic use; Brazilian recommendations; Curitiba, patient advice after care at a UPA, p. 2.
Care and its limits
Care before your appointment and the limits of video consultations
Hydration and comfort measures do not replace treatment for an established infection.
Drink water throughout the day and avoid repeatedly putting off going to the toilet. If you have been advised to restrict fluids because of heart or kidney disease, keep following that plan and confirm the appropriate amount with your care team. There is no need to force yourself to drink large volumes.
Cranberry has been studied for prevention in some recurrent cases; it should not be used to treat an acute infection or to delay assessment. The same caution applies to teas or products sold as a quick solution for cystitis.
If there are no warning signs, a consultation with a general practitioner can help organise assessment. The doctor may refer you for a physical examination, a urine sample or in-person care. Fever, lower back pain and a worsening general condition require a different approach, even if an online appointment is already booked.
Sources: IFF/Fiocruz, prevention of recurrent UTI; Curitiba, advice after treatment, p. 2. FEBRASGO, review of recurrent UTI (2018), cranberry and its limits in acute treatment.
Next step
Choose care according to your symptoms
Warning signs require urgent in-person assessment. For stable symptoms, discuss the appropriate place to start with a healthcare professional.
Bring a summary of your symptoms
Note when symptoms started, fever, recent treatments and allergies. If warning signs develop, seek in-person care.
References
Medical sources consulted
Brazilian sources checked on 27 September 2026. Medical review pending.
The joint recommendations from Brazilian societies guide the clinical discussion. The IFF/Fiocruz material is educational; the Curitiba protocol is municipal, not a national rule for accessing care. Antibiotic doses and regimens are not reproduced.
Questions
Frequently asked questions
Does strong-smelling urine mean an infection?
No. A different smell or colour without urinary symptoms is not enough to diagnose an infection or start an antibiotic. Burning, urgency, pain or other symptoms need assessment.
If the infection has returned, can I repeat the previous prescription?
Seek reassessment. Repeated episodes may require tests and a different strategy; reusing an old prescription can delay identifying the cause.
