Testicular torsion occurs when a testicle rotates and twists the spermatic cord, which carries blood to the testicle. The twisting blocks the flow of blood to the testicle, causing sudden and severe pain and swelling in the scrotum or lower abdomen. The exact cause of testicular torsion is not always clear, but most boys and men who get it have inherited a trait where their testicle moves freely inside their scrotum, known as bell clapper deformity. Other risk factors include:

• Intense activity within hours of the torsion
• Minor injury to the area
• During sleep
• Rapid growth of the testicles during puberty

It is important to note that testicular torsion is a surgical emergency that requires prompt treatment. If left untreated, the condition can lead to a permanently damaged or dead testicle, which must then be removed.