Testicular torsion: symptoms, causes, treatment and why speed matters

The most common symptom is sudden, severe pain in one testicle. Cambridge University Hospitals says the pain is often severe, often comes on suddenly and may be associated with nausea or vomiting, and that it may come and go but tends not to go away. Swelling (especially on one side of the scrotum), redness and abdominal pain can follow.

On examination, Cambridge University Hospitals says the testicle may be sitting higher than usual in the scrotum and be in a more horizontal position than usual. NHS Essex adds tenderness of the scrotum and pain that starts during sport, after injury, or even during sleep.

• Sudden, severe pain in one testicle

• Swelling or redness of the scrotum

• Nausea or vomiting

• Pain low in the abdomen

• A testicle that sits higher than normal

• Pain that wakes someone from sleep

Each testicle hangs in the scrotum on a spermatic cord that carries blood to it. In torsion, the cord twists. Guy's and St Thomas' NHS Foundation Trust describes it as the testicle twisting on itself and cutting off the blood supply, and calls it an emergency needing urgent treatment.

Cambridge University Hospitals explains that in most boys the testicle is attached to the back and bottom of the scrotum, which makes twisting hard. In some, the testicle is not secured at the base, called bell clapper deformity, so it moves more freely. In many boys there is no apparent cause, and nothing they did or did not do brought it on.

Torsion can happen during exercise, during sleep or after an injury. It is most common in teenagers and young men, but it can happen at any age.

Guy's and St Thomas' says sudden, severe testicle pain could be testicular torsion, that it is an emergency and needs treatment urgently, and that not getting urgent treatment might lead to testicle damage or loss of the testicle. NHS Essex advises going straight to A&E, or calling 999 if you cannot get to hospital quickly.

NHS Essex says do not wait to see if the pain improves, do not apply heat, and do not delay seeking help because of embarrassment. It says that in Essex, local data show that on average more than one boy or young man loses a testicle every month because they did not reach an Emergency Department quickly enough, often due to embarrassment, uncertainty or hoping the pain will go away.

NHS Essex gives these typical outcomes by timing: within 6 hours there is a high chance of saving the testicle, after 12 hours the risk of permanent damage increases significantly, and after 24 hours the testicle will usually need to be removed. These timings are a guide, not a deadline; if the pain has been present for longer, still go straight to A&E.

Cambridge University Hospitals explains that in most boys the testicle is attached to the bottom and back of the scrotum, which makes it hard to twist. In some boys the testicle is not secured at the base (bell clapper deformity), so it is freer to move and potentially twist. In many boys there is no apparent cause. Torsion may occur during exercise or during sleep, or after trauma or injury to the testicle.

The same leaflet says it can happen at any age (including before birth in a few boys) but is most common between 10 and 25 years of age. NHS Essex describes it as most commonly affecting boys and young men aged between 10 and 18, but possible in babies and adults. NHS Essex says there is no guaranteed way to prevent it; some people are born with a higher risk because of how the testicles are attached, so the key is recognising symptoms early.

Guy's and St Thomas' says that at hospital staff take a medical history, examine the scrotum and test a urine sample for infection and blood. More tests are not usually helpful because of the urgency. It is difficult to be completely certain that someone has torsion, so surgeons may recommend exploration if they think it likely.

Cambridge University Hospitals says blood tests and ultrasound are not usually required. Where torsion remains a possibility after examination, emergency surgery is advised because of the risk to the testicle if it is left untreated. The Guy's leaflet adds that a scan is not completely accurate and may delay surgery and risk loss of the testicle.

Other causes of a painful testicle include epididymitis, which is inflammation of the tube behind the testicle, and torsion of a small piece of leftover tissue. In about 1 in 10 people having this type of surgery, no twist is found.

The operation is called scrotal exploration. It is done under general anaesthetic. A cut is made in the scrotum, the testicle is examined, untwisted, and watched for the blood supply returning. If healthy, it is stitched in place so it cannot twist again. The other testicle is stitched in the same way to prevent torsion there.

If the testicle has not survived it is removed, which is called orchidectomy. Cambridge University Hospitals says a boy who has lost one testicle should go through puberty normally because the remaining testicle is enough for hormone production, and that one testicle is also enough for fertility.

Guy's and St Thomas' lists possible risks of surgery in up to 10 in 100 people: a stitch that can be felt through the skin, a collection of blood, infection, or ongoing discomfort. Risks in fewer than 2 in 100 include shrinkage of the testicle even when saved, and reduced fertility. It says there are no safe alternatives for suspected torsion.

Most people go home on the same day or the day after. Guy's and St Thomas' says the groin and scrotum may be uncomfortable for 7 to 10 days, usually relieved by simple painkillers. Stitches are usually dissolvable and disappear after about 3 weeks. A scrotal support, tight briefs or cycling shorts for the week after surgery can help reduce the risk of bruising.

The same leaflet advises not doing vigorous exercise, including sports, for 4 to 6 weeks, not soaking in a bath or swimming for 10 to 14 days (showers are fine after 48 hours), and returning to work typically after a week, or longer if work is physical. NHS Essex gives a shorter figure for avoiding strenuous activity (around two weeks), so always follow the instructions from your own hospital.

Cambridge University Hospitals says torsion can happen at any age, including before birth in a few boys, but is most common between 10 and 25 years. It stresses that there is nothing a boy did or did not do that resulted in torsion.

To prevent delay, the operation takes place at the nearest hospital wherever possible. Cambridge University Hospitals says a child may be transferred to a hospital with specialist children's surgeons and anaesthetists because of young age (usually under three years) or an underlying condition. NHS Essex advises young people to tell a parent, teacher or trusted adult immediately and to call 999 if alone, and advises parents to take sudden testicular pain seriously and act quickly.

Torsion is managed through emergency departments and urology or paediatric surgical teams. Cambridge University Hospitals says that to prevent delay the operation takes place at the nearest hospital wherever possible. Younger children, usually under three, or those with underlying conditions, may be transferred to a hospital with specialist children's surgeons and anaesthetists.

Because speed decides the outcome, the nearest emergency department with surgical cover is the right place, not a booked private appointment. An NHS Essex clinician notes that some hospitals can assess but may need to transfer patients for treatment, which can cause delays, so local advice on which A&E to use may apply.