Medically reviewed by Mr Maneesh Ghei, Consultant Urological Surgeon (GMC: 5208045)
Blood in urine can be alarming, and one question people often search for is: what STI causes blood in urine? While blood in urine (haematuria) has many possible causes, certain sexually transmitted infections can inflame and damage the urinary tract enough to cause this symptom. This guide covers which STIs are most commonly involved, what to look out for, and when to seek specialist help.
Key Takeaways
- Blood in urine (haematuria) can be caused by STIs including chlamydia, gonorrhoea, herpes, and trichomoniasis
- Many STIs produce no early symptoms, so blood in urine may be the first sign something is wrong
- Blood in urine alongside urinary symptoms such as burning or discharge should always be investigated promptly
- STIs are not the only cause of haematuria — other urological conditions including kidney stones, bladder issues, and prostate problems can also be responsible
- Only proper testing can identify the actual cause — do not assume or delay
What Is Blood in Urine (Haematuria)?
The medical term for blood in urine is haematuria. Blood may be visible — appearing pink, red, or brown — or detectable only through laboratory testing (microscopic haematuria). Even a small amount of blood warrants investigation, as it can indicate a range of conditions from infection to more serious urological issues.
Which STIs Can Cause Blood in Urine?
Chlamydia
Chlamydia is a bacterial infection that affects the urethra, causing inflammation that can lead to pain during urination, urgency, and sometimes blood in urine. It often shows no early symptoms at all, making regular testing important for sexually active people.
Gonorrhoea
Gonorrhoea infects the urethra, causing urethritis with inflammation and sometimes bleeding. Symptoms include discomfort and burning during urination. In men, it may cause testicular swelling if left untreated.
Genital Herpes
Though primarily known for painful blisters, herpes can cause blood in urine when sores appear on or near the urethra. Caused by herpes simplex virus (HSV), the virus remains in the body for life with periodic flare-ups.
Trichomoniasis
This parasitic infection affects both men and women, causing urinary tract inflammation, burning sensations during urination, and sometimes blood in urine. It requires specific medication for treatment and is often overlooked because symptoms can be mild.
Why Do STIs Lead to Blood in Urine?
Infections cause inflammation and irritation that weakens tiny blood vessels in the urinary tract lining. Conditions like chlamydia and gonorrhoea attack the urethra directly, causing damage that can result in bleeding. Herpes irritates external tissues but affects urination when sores are near the urethral opening.
Other Symptoms to Watch For
If you have blood in urine alongside any of the following, seek medical advice promptly:
- Pain or burning when passing urine
- Frequent urge to urinate
- Discharge from the penis or vagina
- Pelvic pain or discomfort
- Itching or irritation around the genitals
- Sores, blisters, or rashes in the genital area
Is an STI Always the Cause?
No. Blood in urine has many possible causes beyond STIs. A urologist will consider a range of conditions including kidney stones, bladder infections, prostate problems, and in some cases more serious conditions. It is important not to assume the cause without proper testing, as the right diagnosis determines the right treatment.
What to Do If You Notice Blood in Urine
Do not wait to see if it resolves on its own. Blood in urine always warrants investigation. Here is what to do:
1. Book an appointment promptly. Contact your GP, a sexual health clinic, or a private urologist as soon as possible.
2. Be honest during your consultation. Explain all symptoms clearly and mention any potential STI exposure so your provider can choose the right tests.
3. Get tested. Testing may include urine samples, blood tests, and swabs to identify the cause.
4. Follow treatment advice. Complete your full prescribed medication course, even if symptoms ease before you finish it.
If you are in London and looking for specialist urology advice, Mr Maneesh Ghei offers private consultations at The Wellington Hospital, St John’s Wood. No GP referral is required and same-week appointments are usually available.
Private Urology Consultations London
Blood in urine needs a proper diagnosis. Mr Ghei can see you this week.
Whether the cause is an infection, a urological condition, or something else entirely, Mr Maneesh Ghei can investigate and give you a clear answer. Same-week private appointments available across four London hospitals. No GP referral needed.
How to Reduce Your Risk of STIs
- Use condoms during all sexual activity
- Get tested regularly if you are sexually active
- Communicate openly with partners about sexual health
- Seek prompt treatment for any symptoms
Frequently Asked Questions
Is blood in urine always a sign of an STI?
No. Blood in urine (haematuria) has many possible causes, including kidney stones, urinary tract infections, bladder conditions, prostate problems, and in some cases more serious conditions. STIs are one possible cause, but only testing can determine the actual reason. Any episode of blood in urine should be investigated by a healthcare professional.
What does chlamydia do to your urine?
Chlamydia causes inflammation of the urethra (urethritis), which can lead to pain or burning when urinating, increased urgency, and sometimes blood in the urine. Many people with chlamydia have no symptoms at all, which is why regular STI testing is recommended for sexually active people.
Can gonorrhoea cause blood in urine?
Yes. Gonorrhoea infects the urethra and causes urethritis, which can result in bleeding. Other symptoms include a burning sensation when urinating and discharge. In men, untreated gonorrhoea can spread to the testicles and cause swelling and pain. Early treatment is important to prevent complications.
What other conditions can cause blood in urine besides STIs?
Common causes include urinary tract infections (UTIs), kidney stones, bladder infections, prostate conditions including BPH and prostate cancer, bladder cancer, and vigorous exercise. Some medications can also cause haematuria. Because the causes vary widely, proper testing is essential to identify what is actually happening.
Should I go to a GP or sexual health clinic for blood in urine?
Either is appropriate if an STI is a concern. However, if you want a comprehensive urological assessment that looks beyond STIs — including the kidneys, bladder, and prostate — a private urologist can assess the full picture in a single appointment, often with faster access than NHS pathways.
Is blood in urine after sex normal?
No. Blood in urine is not a normal response to sexual activity and should always be investigated. It may indicate urethral irritation, a UTI, an STI, or another urological condition. Do not assume it is harmless and will resolve on its own — seek medical advice.
Where can I see a private urologist in London?
Mr Maneesh Ghei is a consultant urological surgeon based at The Wellington Hospital, Platinum Medical Centre, St John’s Wood, London NW8 7JA. He covers kidney infections, kidney stones, urinary problems, and a wide range of urological conditions. Same-week appointments are available with no GP referral needed.
About the Author
Mr Maneesh Ghei, Consultant Urological Surgeon (GMC: 5208045)
Mr Maneesh Ghei is a consultant urological surgeon with NHS and private practice across four London hospitals. He specialises in the diagnosis and management of kidney infections, urinary tract conditions, kidney stones, prostate conditions, and male sexual health. Mr Ghei sees new patients privately with same-week availability. No GP referral is required. Book a private urology consultation.
Need help to book a consultation or got an enquiry regarding what tests you may need?
Fill in your details and we will contact you
🔒 Your data is secure. We’ll only use it to arrange your appointment.
