References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Urine chemistry tests check for various substances in urine that can indicate infection, kidney function, blood sugar levels, hydration and other health markers. While not specifically an STI test, urine chemistry is sometimes part of sexual health assessment, particularly when investigating symptoms like burning on urination or unusual urine appearance.
Here’s what they show.
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What Urine Chemistry Tests Check
| Marker | What It Indicates |
|---|---|
| Leucocytes (white blood cells) | Possible infection or inflammation |
| Nitrites | Bacterial infection (UTI) |
| Blood | UTI, kidney problems, stones, sometimes harmless |
| Protein | Kidney function, infection |
| Glucose | Diabetes |
| Ketones | Diabetes, fasting |
| pH | Acidity/alkalinity — varies with diet and conditions |
| Specific gravity | Hydration status |
How It’s Done
- Dipstick — paper strip dipped into urine, changes colour according to substances present
- Microscopy — looking at urine under a microscope for cells, crystals, bacteria
- Culture — growing bacteria to identify infection
- Lab chemistry — quantitative measurement of specific substances
Urine Tests in Sexual Health
In sexual health clinics, urine is used for:
- NAAT testing for chlamydia, gonorrhoea and trichomoniasis
- Pregnancy testing
- Drug testing in specific scenarios
- Checking for UTI when symptoms are present
What Symptoms Prompt Urine Testing
- Burning or pain on urination
- Unusual urine smell
- Cloudy or bloody urine
- Frequent urination
- Lower abdominal pain
- Possible STI symptoms
UTI vs STI
Urine chemistry can quickly distinguish UTI from STI:
- UTI typically shows leucocytes and nitrites positive
- STI may show leucocytes but usually not nitrites
- NAAT testing on urine confirms STI diagnosis
Home Urine Test Strips
Home urine test strips are available from pharmacies. They give immediate basic results but don’t replace clinic testing for serious symptoms or full diagnosis.
What Results Mean
- Normal — no concerning markers detected
- UTI suggested — typically leucocytes plus nitrites
- Diabetes possible — glucose or ketones detected
- Kidney concern — protein or significant blood
- STI possible — leucocytes without nitrites; further testing needed
Read more: Home UTI tests | Frequent urination and STIs | Yeast vs UTI
Frequently Asked Questions
Can urine tests detect STIs?
Some — chlamydia, gonorrhoea and trichomoniasis can be tested via urine NAAT.
What does protein in urine mean?
Could indicate kidney issues, infection or temporary causes. Persistent protein needs investigation.
Why do I need to give a urine sample?
It’s a non-invasive way to check for many health markers and STIs.
Related reading
- A to Z of Sex: Sexual Health Terms Explained
- Alcohol and HIV: What You Need to Know
- Anxiety and HIV: Coping and Getting Support
- Are All STIs Curable?
- Blood Problems and HIV: Anaemia, Low Platelets and More
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
