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Torsion of the testis

Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Testicular torsion article more useful, or one of our other health articles.

Torsion of the testis may more accurately be called torsion of the spermatic cord. It causes occlusion of testicular blood vessels and, unless prompt action is taken, rapidly leads to ischaemia, resulting in loss of the testis (germ cells are the most susceptible cell line to ischaemia).

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  • Torsion occurs in boys of any age. It can occur in the first year of life but most commonly in those aged 12-18 years, with peak incidence between 13-16 years1.

  • Annual incidence in the USA is 1 per 4,000 males younger than 25 years of age.

  • There were 3,304 episodes of torsion of the testis in England in 2013/14, of which 2,501 were in children.

  • 4-8% of torsions are caused by trauma.

  • Some boys and men give a history of previous episodes of severe, self-limiting scrotal pain and swelling, which is assumed to be spontaneous torsion and resolution.

Risk factors

Two types of testicular torsion may occur: intravaginal and extravaginal.

Intravaginal torsion is secondary to the lack of normal fixation of the posterior lateral aspect of the testes to the tunica vaginalis. This results in the testis being free to swing and rotate within the tunica vaginalis of the scrotum. This defect is referred to as the 'bell-clapper deformity' which is the most common predisposing factor for torsion1. This occurs in 12% of all males and is bilateral in around 40% of cases. A high insertion of the tunica vaginalis produces a 'bell-clapper testis' with a horizontal lie rather high in the scrotum. This lie, with the long axis in the horizontal rather than the vertical plain, is usually bilateral.

Extravaginal torsion occurs more often in neonates and occurs in utero or around the time of birth before the testis is fixed in the scrotum by the gubernaculum. Consequently, both the spermatic cord and the tunica vaginalis undergo torsion together, typically in or just below the inguinal canal.

There may be a genetic factor in some cases of torsion.

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The sensible clinician should have a very low threshold for suspecting testicular torsion in a boy or man presenting with acute, painful scrotal swelling, particularly if he is younger than 25 years of age.


  • There is typically sudden, severe pain in one testis.

  • There may be lower abdominal pain and, in any boy presenting with abdominal pain, the testes should be checked2.

  • It often comes on during sport or physical activity.

  • There is quite often a history of previous, brief episodes of similar pain. This is presumably torsion that corrected itself.

  • Nausea and vomiting often occur.

  • Occasionally, the symptoms are milder and less acute.

  • Easing pain is not necessarily a good sign of spontaneous resolution. Pain also eases as necrosis sets in.

  • A history of recurrent attacks of severe pain that resolved spontaneously might suggest intermittent testicular torsion and de-torsion.


Examination is often helpful but normal findings should not preclude further investigation if clinical suspicion is high.

  • There is usually reddening of the scrotal skin.

  • There is a swollen, tender testis retracted upwards.

  • Lifting the testis up over the symphysis increases pain, whereas in epididymitis this usually relieves pain.

  • In the early stages, the epididymis may be felt in an abnormal anterior rather than typical posterior position but this depends upon the degree of torsion that may be from 180-720°. Later, gross swelling prevents this finding.

  • The testes on both sides are characteristically in the 'bell-clapper position' with a horizontal long axis.

  • Looking for absence of the cremasteric reflex is a simple method with 100% sensitivity and 66% specificity for testicular torsion.

  • The cremasteric reflex (L1/L2 spinal nerves) is elicited by gentle pinching or stroking of the inner thigh while observing the scrotal contents.

  • If the torsion occurs prenatally, the baby is born with a firm, hard, non-transilluminable scrotal mass. There are no symptoms. The scrotal skin is usually fixed to the underlying necrotic testis.

Differential diagnosis

  • Torsion of testicular or epididymal appendage:

    • This usually occurs in boys aged between 7 and 12 years.

    • Systemic symptoms are rare.

    • There is usually localised tenderness but only in the upper pole of the testis.

    • Occasionally, the 'blue dot sign' is present in light-skinned boys (ie a tender nodule with blue discolouration on the upper pole of the testis).

  • Epididymitis, orchitis, epididymo-orchitis:

    • These conditions most commonly occur from the reflux of infected urine or from sexually acquired disease caused by gonococcus and Chlamydia spp. Hence, they tend to affect an older age group.

    • NB: patients with acute epididymitis usually experience a tender epididymis, whereas patients with testicular torsion are more likely to have a tender testicle.

  • Hydrocele:

    • Swelling is usually painless.

    • The scrotum will transilluminate.

  • Incarcerated hernia:

    • This may be diagnosed by careful examination of the inguinal canal.

  • Testicular tumour:

    • Scrotal enlargement occurs more slowly.

    • It is only rarely accompanied by pain. Typically, the normal slightly delicate sensation of the testis is absent.

  • Mumps:

    • There is swelling of the parotid glands in mumps.

    • Mumps orchitis is rare before puberty.

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European Association of Urology (EAU) guidelines state that Doppler ultrasound is useful to evaluate acute scrotum, with 63.6-100% sensitivity and 97-100% specificity, a positive predictive value of 100% and negative predictive value of 97.5%3. A positive 'whirlpool sign' is defined as the presence of a spiral-like pattern when the spermatic cord is assessed during ultrasonography and has 99% specificity for the presence of testicular torsion4.The use of Doppler ultrasound may reduce the number of patients with acute scrotum undergoing scrotal exploration, but it is operator-dependent and can be difficult to perform in pre-pubertal patients. It may also show a misleading arterial flow in the early phases of torsion and in partial or intermittent torsion. Additionally, persistent arterial flow does not exclude testicular torsion. A comparison with the other side should always be done.

However, UK guidelines from the Royal College of Surgeons state that 'in patients with a history and physical examination suggestive of torsion, imaging studies should NOT be performed as they may delay treatment, therefore prolonging the ischaemic time'5. Negative surgical exploration is preferable to a missed diagnosis as all imaging studies have a false-negative rate.The literature suggests a high degree of sensitivity and specificity can be attained with Doppler ultrasound. Doppler ultrasound may nevertheless be falsely reassuring in the early phase of torsion and in partial or intermittent torsion: present arterial flow does not exclude testicular torsion. Imaging may be considered for a small number of children under the guidance of a senior clinician in late presenters or in those with atypical features.


  • All cases of acute testicular pain are due to torsion until proved otherwise. If torsion is suspected after a prompt clinical assessment, a scrotal exploration should be carried out without delay.

  • An immediate referral must be made to the emergency urology or surgical team1. Before further assessment, food should be withheld and patients provided with adequate analgesia.

  • It may be possible to reduce the torsion manually. It should initially be done by outwards rotation of the testis unless the pain increases or if there is obvious resistance3. Success is defined as the immediate relief of all symptoms and normal findings at physical examination. If unsuccessful, further manual de-torsion may be attempted as the testicle can twist 180°6.

  • Bilateral orchiopexy is still required after successful de-torsion. This should not be done as an elective procedure but rather immediately following de-torsion.

  • Testicular torsion is an urgent condition, which requires prompt surgical treatment. The two most important determinants of early salvage rate of the testis are the time between onset of symptoms and de-torsion, and the degree of cord twisting.

  • After 24 hours there is controversy as to whether the testis should be removed or fixed, even if it shows some viability, as there is some evidence that orchiectomy is more likely to preserve the function and fertility of the ipsilateral testis. About 20-40% of cases of testicular torsion result in an orchiectomy6. The risk of losing a testis is much higher among African Americans and younger males.

  • If the testis is viable then orchidopexy is usually performed to prevent recurrence, although there is no consensus about this, as the evidence base is small.

  • Whether the affected testis is removed or conserved, the contralateral one should undergo orchidopexy, as the risk of recurrence on the other side is otherwise high.

  • A baby born with testicular torsion should have the affected testis removed (because it is always non-viable) and orchidopexy of the other side (because bilateral torsion is common).


  • Complications of an untreated or delayed torsion include infarction of the testicle with subsequent atrophy, infection and cosmetic deformity.

  • Patients require follow-up mainly for fertility issues and hormonal consequences. Despite timely and adequate detorsion and fixation of the testicle, up to half of the patients may develop testicular atrophy, even when intraoperatively assessed as viable, and should be counselled accordingly.

  • Fertility results vary. Unilateral torsion of the testis seriously impaired subsequent spermatogenesis in about 50% of the patients and produced borderline impairment in another 20%3.

  • Subfertility is found in 36-39% of patients after torsion3. Semen analysis may be normal in only 5-50% in long-term follow-up. Early surgical intervention (mean torsion time less than thirteen hours) with de-torsion was found to preserve fertility, but a prolonged torsion period (mean 70 hours) followed by orchiectomy jeopardised fertility.


  • The extent and duration of torsion have a major influence on both the immediate salvage rate and late testicular atrophy.

  • Testicular salvage rates are 90-100% with surgical correction within six hours of onset of testicular torsion, whereas salvage rates are 10% at 12-24 hours7.

  • One study reported successful harvesting of semen from a subjectively dead testicle, indicating that salvage and cryopreservation of semen should be attempted in all but the most hopeless cases8.

  • The absence of a testis may still have a significant psychological effect and so it is usual to implant a prosthesis if orchidectomy is required. This is usually delayed for six months to let inflammation subside and it is usually inserted via an inguinal incision.


  • Recurrent, intermittent pain, with a 'bell-clapper' testis, requires orchidopexy.

  • Chronic intermittent torsion can result in segmental ischaemia of the testis1.

  • Delay has a considerable adverse effect on survival of the testis and late presentation is a substantial problem.

Further reading and references

  • Thakkar HS, Yardley I, Kufeji D; Management of Paediatric Testicular Torsion - Are we adhering to Royal College of Surgeons (RCS) recommendations. Ann R Coll Surg Engl. 2018 May;100(5):397-400. doi: 10.1308/rcsann.2018.0041. Epub 2018 Mar 15.
  • Laher A, Swart M, Honiball J, et al; Near-infrared spectroscopy in the diagnosis of testicular torsion: valuable modality or waste of valuable time? A systematic review. ANZ J Surg. 2020 May;90(5):708-714. doi: 10.1111/ans.15402. Epub 2019 Sep 11.
  • Pomajzl AJ, Leslie SW; Appendix Testes Torsion
  1. Scrotal pain and swelling; NICE CKS, September 2020 (UK access only)
  2. Vasconcelos-Castro S, Soares-Oliveira M; Abdominal pain in teenagers: Beware of testicular torsion. J Pediatr Surg. 2020 Sep;55(9):1933-1935. doi: 10.1016/j.jpedsurg.2019.08.014. Epub 2019 Aug 29.
  3. EAU Paediatric Urology Guidelines. Edn. presented at the EAU Annual Congress Copenhagen; European Association of Urology, 2018 - updated 2023
  4. McDowall J, Adam A, Gerber L, et al; The ultrasonographic "whirlpool sign" in testicular torsion: valuable tool or waste of valuable time? A systematic review and meta-analysis. Emerg Radiol. 2018 Jun;25(3):281-292. doi: 10.1007/s10140-018-1579-x. Epub 2018 Jan 15.
  5. Management of Paediatric Torsion; Commissioning guide, East Midlands Clinical Network (2016, updated 2019)
  6. Schick MA, Sternard BT; Testicular Torsion
  7. Keays M, Rosenberg H; Testicular torsion. CMAJ. 2019 Jul 15;191(28):E792. doi: 10.1503/cmaj.190158.
  8. Woodruff DY, Horwitz G, Weigel J, et al; Fertility preservation following torsion and severe ischemic injury of a solitary testis. Fertil Steril. 2010 Jun;94(1):352.e4-5. Epub 2010 Feb 13.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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