Urinary Tract Infections Antibiotics, recurrent UTIs and testing in London.
Burning when you urinate, urgency or infections that keep returning? Understand your next steps and explore urine analysis, microscopy and culture at MDC.
Check whether you need urgent care first
Seek an urgent GP assessment or contact NHS 111 for fever, shaking chills, pain in your side or back below the ribs, vomiting, blood in your urine or rapidly worsening symptoms.
Prompt assessment is also important if you are pregnant, male, a child, aged 65 or over, or have diabetes, a catheter or a weakened immune system.
Call 999 for confusion, marked drowsiness or difficulty speaking with a suspected infection. Do not wait for a private test or culture result.
What is a urinary tract infection?
A UTI is an infection affecting part of the urinary system. A bladder infection is often called cystitis. Infection involving the kidneys needs a different assessment and treatment approach.
Burning or stinging
Pain when passing urine is a common symptom, but it can also have causes other than a UTI.
Frequency and urgency
You may need to urinate more often or feel a sudden, difficult-to-ignore urge.
Changes in urine
Cloudiness or blood can occur. Smell or dark colour alone does not establish an infection.
What is the best antibiotic for a urinary tract infection?
There is no single best antibiotic for every UTI. The choice depends on the infection site, pregnancy, kidney function, allergies, previous treatment and likely bacterial resistance.
For uncomplicated lower UTIs in non-pregnant adult women, NICE lists nitrofurantoin or trimethoprim when resistance risk is low as first-choice options. A prescriber must decide which is suitable.
Bladder and kidney infections differ
Nitrofurantoin is used for suitable lower UTIs. It is not appropriate for a suspected kidney infection or prostate infection.
Culture can guide the choice
When indicated, culture and susceptibility testing can help a clinician select an antibiotic likely to work against the organism found.
Review treatment if symptoms persist
Seek reassessment if symptoms worsen at any time or do not start improving within 48 hours of antibiotics. Do not switch medicines or use leftovers yourself.
Urinalysis, microscopy or culture?
Urinalysis
Checks features such as blood, protein and chemical markers. It can support assessment but does not identify which antibiotic will work.
Microscopy
Looks for cells and other findings in the sample. White blood cells can indicate inflammation, which is not always caused by bacterial infection.
Culture
Attempts to grow organisms from the urine. A clinically significant result can support identification and antibiotic susceptibility testing.
Find the right MDC service
Urine Analysis, Microscopy & Culture
£99
Explore the combined urine investigation for suspected, persistent or recurrent infection.
Test code: MLUAC. The service page lists results in 3–5 working days. Confirm current timing and whether susceptibility testing is included when significant bacterial growth is found.
All Urine Tests
Browse MDC’s urine testing services if your clinician has requested a particular investigation.
Unsure which option matches your request? Contact MDC before booking to avoid choosing a test that does not answer your clinical question.
Sexual Health Testing
Burning urination may also occur with a sexually transmitted infection, especially with discharge or a relevant sexual exposure.
Routine urine culture does not replace specific chlamydia or gonorrhoea testing.
What are recurrent urinary tract infections?
Recurrent UTI in adults generally means two or more infections in six months, or three or more in twelve months. Repeated symptoms deserve review rather than repeated courses of the same antibiotic without reassessment.
Review the evidence
Bring previous culture reports, antibiotic names and a record of symptoms. Your clinician can assess whether episodes represent new infections, relapse or another condition.
Consider contributing factors
These may include menopausal changes, incomplete bladder emptying, stones or triggers related to sex. Investigations depend on the individual.
Make a prevention plan
Options may include vaginal oestrogen around or after menopause, methenamine hippurate in selected patients, or targeted antibiotic prevention. These need clinical assessment.
How should I prepare for a urine culture?
Tell the team about treatment
Antibiotics can reduce bacterial growth in a culture. Ideally collect the sample before treatment, but never delay urgent care to do this.
Usually a midstream sample
Routine UTI culture generally uses a clean-catch midstream sample in a sterile container. Avoid touching the inside of the container or lid.
Get the sample to the laboratory promptly
Ask MDC about collection, storage and transport. STI urine tests may need a different collection method, so explain which tests you require.
Common UTI questions
Does a negative culture mean nothing is wrong?
No. Recent antibiotics, sample factors or another cause can explain persistent symptoms. Arrange reassessment rather than ignoring symptoms or automatically repeating antibiotics.
Does finding bacteria always mean I need antibiotics?
No. Bacteria without urinary symptoms usually do not need treatment. Pregnancy and certain planned urological procedures are important exceptions requiring clinical advice.
Can blood tests diagnose a simple bladder infection?
Blood tests are not usually needed for uncomplicated cystitis. A clinician may request kidney function or other blood tests for suspected complications or relevant medical conditions.
Explore MDC blood testsWhat if there is blood in my urine?
Arrange prompt medical assessment. Blood that persists or returns after infection treatment needs further investigation rather than being assumed to be another UTI.
Urine testing at 73 Baker Street
73 Baker Street
London W1U 6RD
Contact the team before travelling to confirm your appointment and sample arrangements.
