Why is sudden testicular pain treated as an emergency?
Sudden, severe testicular pain is assumed to be testicular torsion until a doctor proves otherwise, because torsion happens when the testicle twists on its own blood supply and starts to lose circulation. This can happen at any time, including during or shortly after sex, and it is not caused by an infection or an STI. Without surgery, usually within about 4 to 6 hours of the pain starting, the affected testicle can be permanently damaged and may need to be removed. If you have sudden, severe, one-sided testicular pain, with or without swelling, nausea or vomiting, call 999 or go straight to A&E. Do not wait to see if it settles, and do not book a sexual health appointment for this.
What if the pain came on gradually instead?
If pain built up gradually over hours or days, rather than arriving suddenly and severely, it's less likely to be torsion and more likely to be an infection or irritation that a sexual health clinic can help with. The distinction that matters most is speed of onset and severity: sudden and severe means A&E; gradual, milder and improving on its own is more likely something that can wait for a routine or same-day clinic appointment. If you're ever unsure which one you're dealing with, treat it as the emergency and get seen urgently, because torsion cannot be diagnosed by description alone.
Could it just be arousal, with no infection involved?
Yes, this is common and harmless. Prolonged arousal without ejaculation can cause a dull, heavy ache or pressure in the testicles and lower pelvis, sometimes called testicular congestion. It happens because blood flow increases to the area during arousal and takes a while to disperse if sex doesn't end in ejaculation. It typically settles on its own within a few hours, does not cause swelling, redness or fever, and needs no treatment. If the pain keeps recurring, lasts longer than that, or comes with swelling, get checked rather than assuming it's congestion.
What is epididymitis, and how does it connect to sex?
Epididymitis is inflammation of the epididymis, the coiled tube behind the testicle that stores and carries sperm, and in sexually active men under 35 it is most commonly caused by chlamydia or gonorrhoea. In older men it is more often linked to a urine infection. It typically causes pain and swelling in one testicle that builds up over hours to days, sometimes with a red, warm or tender scrotum, pain when urinating, or discharge from the penis. Left untreated, it can lead to an abscess, chronic pain, or in bilateral or recurrent cases, reduced fertility. It is treated with antibiotics chosen for the underlying cause, usually with good results once treatment starts.
The table below helps separate the three main causes.
What testicular pain after sex is likely to mean:
Which tests are relevant if it looks like epididymitis?
A chlamydia test is the starting point, since chlamydia and gonorrhoea are the two infections most commonly behind epididymitis in sexually active men under 35. Book a gonorrhoea test alongside it. Both are urine tests at Sexual Health Clinic London, £104 each, with results back in 3 days; you'll need to avoid urinating for around 2 hours beforehand for an accurate sample. If you'd rather cover a wider range of infections in one visit, the men's screening package starts at £250 and includes both chlamydia and gonorrhoea alongside HIV and syphilis, as part of our private STI testing in London service.
When should I see a clinician rather than testing alone?
Book to be seen, not just tested, if you have any swelling, redness, warmth, fever, or pain that is getting worse rather than better, because epididymitis benefits from a physical examination alongside the test. Aim to be seen the same day for these symptoms; sudden severe pain still means A&E, not a booking here, and if you cannot tell whether the pain came on suddenly, treat it as an emergency. Mild, settling symptoms without swelling or fever can reasonably start with a test alone, with a follow-up review if anything changes.
How testing works at our Harley Street clinic
A chlamydia or gonorrhoea test is £104 each, taken as a urine sample, with results back in 3 days. If you want a wider check for peace of mind, the men's screening package starts at £250 (Bronze) and covers chlamydia, gonorrhoea, HIV and syphilis; higher tiers add further infections if you'd rather cover more in one visit. Every men's package includes a consultation with a doctor, testing, and treatment if required. Walk-in appointments are available seven days a week at 117a Harley Street, or you can book online.
Book a men's screening package at 117a Harley Street: from £250, includes chlamydia and gonorrhoea.
References
- Testicular torsion, NHS
- Epididymitis and orchitis, NICE Clinical Knowledge Summaries
- UK national guideline for the management of epididymo-orchitis, British Association for Sexual Health and HIV (BASHH)
- Chlamydia and gonorrhoea, NHS
