[1][2] In newborns, pain is often absent and instead the scrotum may become discolored or the testicle may disappear from its usual place.

[1][3] Other risk factors include a congenital malformation known as a "bell-clapper deformity" wherein the testis is inadequately attached to the scrotum allowing it to move more freely and thus potentially twist.

[2] The testicle may lie higher in the scrotum due to twisting and subsequent shortening of the spermatic cord[6] or may be positioned in a horizontal orientation.

[8] There may be a history of previous, similar episodes of scrotal pain due to prior transient testicular torsion with spontaneous resolution.

[6] Most of those affected with testicular torsion have no prior underlying health problems or predisposing conditions.

A larger testicle either due to normal variation or testicular tumor increases the risk of torsion.

Other anatomic risk factors include a horizontal lie of the testicle or a spermatic cord with a long intrascrotal portion.

[7]: 150  Though less pressing, such individuals are at significant risk of complete torsion and possible subsequent orchiectomy and the recommended treatment is elective bilateral orchiopexy.

Ninety-seven percent of patients who undergo such surgery experience complete relief from their symptoms.

[19]: 315  The exact cause of or specific risk factors for extravaginal torsion in this population remains unclear.

[2] Intravaginal testicular torsion occurs when the testicle rotates on the spermatic cord within the tunica vaginalis.

The "bell-clapper deformity," in which there is inappropriately high attachment of the tunica vaginalis over the spermatic cord and failure of the normal posterior attachment of the testicle to the inner scrotum, which allows the testicle to move freely within the tunica vaginalis and predisposes to intravaginal testicular torsion.

[19] This type of torsion is the most common cause of acute scrotal pain in boys ages 7–14.

Palpation reveals a small firm nodule on the upper portion of the testis which displays a characteristic "blue dot sign".

[2] Immediate surgery is recommended regardless of imaging findings if there is a high degree of suspicion based on history and physical examination.

[20] Prehn's sign, a classic physical exam finding, has not been reliable in distinguishing torsion from other causes of testicular pain such as epididymitis.

[citation needed] A Doppler ultrasound scan of the scrotum can identify the absence of blood flow in the twisted testicle and is nearly 90% accurate in diagnosis.

[22] Radionuclide scanning (scintigraphy) of the scrotum is the most accurate imaging technique, but it is not routinely available, particularly with the urgency that might be required.

[24] Testicular torsion is a surgical emergency that requires immediate intervention to restore the flow of blood to the testicle.

[3] Typically, when a torsion takes place, the surface of the testicle has rotated towards the midline of the body.

[citation needed] When salvage of the testicle is accomplished, long-term testicular damage is common.

[10] A repeat doppler ultrasound scan may confirm restoration of blood flow to the testicle following manual detorsion.

[27] It is the most common cause of rapid onset testicular pain and swelling in people under 18 years old.