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.
Testicular pain has many possible causes, some related to STIs and some not. The most important thing is to distinguish between urgent causes (like testicular torsion, a surgical emergency) and less urgent ones (like epididymitis or muscle strain). Any sudden severe testicular pain needs immediate medical attention.
Order a discreet home STI test
Common Causes
| Cause | Features | Urgency |
|---|---|---|
| Testicular torsion | Sudden severe pain, nausea | A&E immediately |
| Epididymitis (STI) | Gradual pain, swelling, possible discharge | Same-day clinic |
| Orchitis | Testicular inflammation, fever | Same-day |
| Varicocele | Dull ache, “bag of worms” feeling | Routine GP |
| Trauma | Pain after injury | Based on severity |
| Kidney stones | Referred pain from back/side | Urgent if severe |
| Cancer | Painless lump (sometimes dull ache) | Urgent GP |
When It’s an Emergency
- Sudden severe pain
- Pain with nausea/vomiting
- Testicle higher or twisted
- Under 25 — torsion is more common
- Go to A&E — don’t wait
STI-Related Testicular Pain
Chlamydia and gonorrhoea can cause epididymitis — inflammation of the tube behind the testicle. Symptoms include gradual onset pain, swelling, possible discharge and pain on urination. Testing and antibiotic treatment are needed.
Self-Examination
- Check testicles monthly for lumps
- Painless lumps should be checked by a GP
- Most lumps are not cancer but need investigation
When to Seek Help
- Any new or persistent testicular pain
- A new lump or swelling
- Pain with fever or discharge
- Sudden severe pain — A&E immediately
Read more: Testicular pain and STIs | What is chlamydia? | When to go to A&E
Frequently Asked Questions
Is testicular pain always serious?
Not always, but it should always be assessed.
Can STIs cause testicular pain?
Yes — chlamydia and gonorrhoea can cause epididymitis.
How do I know if it’s torsion?
Sudden severe pain, especially in young men. Don’t wait — go to A&E.
Related reading
- Is Testicular Pain a Sign of an STI?
- Common STI Symptoms in Women
- Abnormal Genital Discharge and Chlamydia
- How Accurate Are Rapid HIV Tests?
- Anonymous STI Testing: What It Means
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.
