Am I Suffering from a Testicular Infection?

마지막 업데이트: 8월 29, 2026

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A painful, swollen testicle is one of the commoner reasons men come to see me. It is usually an infection, and it usually affects one side only — both testicles being infected at the same time is unusual. In practice the testicle is rarely the only organ involved: the infection almost always involves the epididymis alongside it.

Before Anything Else: The Diagnosis That Must Be Excluded First

Sudden severe testicular pain can also be 고환 염전, where the testicle twists on its own blood supply. That is a surgical emergency, and the tissue begins to die within hours. If the pain came on suddenly and severely, go to an emergency department now rather than waiting to see whether it settles. In Thailand, call 1669.

The clinical patterns help. Torsion is more typical in younger males, usually arrives abruptly at full intensity — often waking someone from sleep — commonly brings nausea or vomiting, and usually comes without fever or urinary symptoms. An infection builds more gradually and often comes with fever or burning on passing urine. But those patterns are tendencies, not rules, and they are not reliable enough to bet a testicle on.

An important correction to the earlier version of this page. It said that where there is doubt, an urgent scrotal ultrasound settles the question. That is not right, and it is the single most consequential error this article contained. A normal Doppler ultrasound does not exclude torsion — blood flow can still be detected in a testicle that is twisted, particularly where the rotation is partial or the scan is done early, and the quality of the study depends heavily on who performs it. Torsion is a clinical diagnosis. Where the history and examination point to it, the correct step is surgical exploration, not reassurance from a scan. If you are told your scan was normal but the pain began suddenly, is severe and is not settling, say so and ask to be seen by a urologist before you are sent home. The full account, including how salvage rates fall with each hour, is in testicular torsion: sudden severe pain in one testicle is an emergency.

One related pattern is worth mentioning to your doctor even when nothing hurts today: repeated brief attacks of severe testicular pain that resolve on their own within minutes to an hour. That is 간헐적 비틀림, and because the episodes settle they are usually dismissed — yet they identify anatomy that can be fixed as a planned operation before the episode that does not resolve.

The epididymis is a coiled tubular structure attached to the back and upper part of each testicle, where sperm mature before ejaculation. Because the two structures sit so close together, infection commonly affects both — which is why the medical term is epididymo-orchitis.

Where the infection comes from

The mechanism resembles a bladder infection: bacteria travel backwards from the urethra into the genital tract. In older men this is usually E. coli, and it raises the question of whether anything is obstructing the flow of urine. In younger, sexually active men the leading causes are sexually transmitted infections — chlamydia and gonorrhoea — which is why a urine PCR panel is often the more useful test in that group. Heavy or repetitive physical exertion is sometimes blamed; strain can certainly aggravate the pain, but it is not an established cause on its own and should not be allowed to explain away a swollen testicle.

The viral cause that is often forgotten: mumps

Not every testicular infection is bacterial. Mumps can inflame the testicle, and it is commoner than most people expect in an unvaccinated or incompletely vaccinated male past puberty. Historical figures from before routine vaccination put orchitis in a wide range around 15% to 30% of post-pubertal males with mumps; in outbreaks in vaccinated populations the figure has been far lower, in the region of 3% to 10%. It is rare before puberty.

It typically begins four to eight days after the parotid glands swell, although intervals of up to several weeks have been reported — and it can occur without any obvious swelling of the face at all, which is how the diagnosis gets missed. It affects one side in the large majority of cases, roughly 60% to 80%, and both sides in the remainder.

This matters for two reasons. Antibiotics do nothing for it, so a man treated as though he had a bacterial infection does not improve and is often given a second and third course. And unlike bacterial infection, it can leave lasting effects: some reduction in the size of the affected testicle occurs in up to about half of cases, and abnormalities on a semen analysis in up to about a quarter.

The reassurance that belongs beside those numbers, because it is the part men actually want: a smaller testicle and an abnormal semen result are not the same as being unable to father a child. Sterility is rare, even when both testicles were affected. If it worries you, a semen analysis some months after recovery answers the question for you specifically rather than in the abstract. Treatment is supportive: rest, scrotal support, anti-inflammatory medication and time. Vaccination is what prevents it.

How testicular infection is treated

Treatment follows the organism most likely to be responsible, and the two groups are treated quite differently. Getting that split right at the first visit matters more than anything else in the management.

1. Where a sexually transmitted organism is likely — a younger, sexually active man — the current standard is an injection of ceftriaxone together with a course of oral doxycycline, which covers gonorrhoea and chlamydia respectively. A single antibiotic does not cover both. Current sexual partners need testing and treatment too, otherwise reinfection follows; what that involves in practice is set out in the article on gonorrhoea treatment.
2. Where an enteric organism such as E. coli is likely — an older man, a man with an obstructing prostate, or after urological instrumentation — a fluoroquinolone such as levofloxacin or ofloxacin is used, adjusted once the urine culture identifies the organism.
3. Where both are plausible, which is not unusual, the regimens are combined rather than chosen between.

Doses and durations are set by the treating doctor and are not given here. Mumps orchitis, being viral, is not treated with any of this.

A word about fluoroquinolones. Where they are the right choice, they are an effective one, but they are not a harmless class. Regulators in the United States and Europe carry warnings about tendon inflammation and rupture, aortic aneurysm and dissection, peripheral nerve damage, effects on the central nervous system, disturbances of blood sugar and prolongation of the heart’s QT interval, and they can provoke a difficult bowel infection. Practical consequences: new pain in a tendon — most often the heel — means stopping the drug and being reviewed the same day, and so does sudden severe pain in the abdomen, chest or back, or new numbness, tingling or burning in the hands or feet, since nerve damage from this class can be permanent. Finish a course that is genuinely indicated; do not accept repeat courses for a testicle that was never proven to be infected.

Pain is managed well with anti-inflammatory medication, scrotal support and ice packs. One point is worth telling every patient in advance: when treatment is working, the pain settles first, but the scrotal swelling can take weeks to months to resolve completely. That lag is normal and does not mean the treatment has failed.

Come back sooner rather than later

Return for review, or attend an emergency department, if the pain worsens despite antibiotics, if a high fever or shaking chills develop or you feel systemically unwell, or if the scrotum becomes red, tense or increasingly swollen. These can signal an abscess or a more serious infection that antibiotics alone will not settle. Rapidly spreading redness of the scrotum with severe pain and feeling very unwell needs the emergency department immediately rather than a clinic appointment. In Thailand, call 1669.

There is one further reason not to let this drift. A lump that is still there after the infection has settled is not part of the infection and needs assessing. Testicular tumours are usually painless, but not always, and an episode of pain is a common moment for a man to notice a lump he then attributes entirely to the infection. If anything firm remains once everything else has resolved, have it examined. Persistent testicular discomfort with everything normal on testing is a different problem again — that is 음낭 통증 증후군.

Once the patient is improving, the underlying cause still needs identifying — that is what prevents the next episode. That means safe sex practices and partner treatment where an STI was responsible, and in older men an assessment of whether the bladder is emptying properly or anything is obstructing it. Testing and vaccination services are described on the STI testing and treatment page.

If you are dealing with this, see a urologist rather than waiting it out — and if the pain began suddenly and severely, treat it as an emergency.

If you have painful or swollen testicles and would like proper diagnosis and treatment, Dr. Soarawee Weerasopone offers specialist consultations at 방콕 병원 본사. Appointments at Samitivej Sriracha Hospital in Chonburi can be arranged by calling the Urology department on 088-022-1445.

Bangkok Hospital Telemedicine is available for non-urgent consultations, including for international patients — arrange it in advance by email to the Urology department at bhquro@bdms.co.th. Samitivej Sriracha is in-person only. Enquiries about cost are answered by the hospital rather than through this website. An acutely painful testicle is not a telemedicine problem — it needs examining in person, today.

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참고 문헌

• Justice ED, Fricker J, Ross JDC, et al. The 2024 European guideline on the management of epididymo-orchitis. J Eur Acad Dermatol Venereol. 2025.
• Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1–187.
• Hviid A, Rubin S, Mühlemann K. Mumps. Lancet. 2008;371(9616):932–944.

고지 사항: This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for general education only and does not constitute medical advice, diagnosis or treatment for any individual, and it gives no doses. Sudden severe testicular pain is a medical emergency — attend an emergency department immediately rather than waiting for an appointment, and do not be reassured by a normal ultrasound if the pain fits. No advice, diagnosis or prescription is given through personal messaging channels or social media, and Dr. Soarawee operates no public social media account. Always consult a qualified doctor about your own symptoms. In an emergency in Thailand, call 1669.