Epididymitis: symptoms, causes and treatment

The NHS lists sudden or gradual pain in 1 or both testicles, the scrotum (the bag of skin containing the testicles) feeling tender, warm and swollen, and a build-up of fluid around the testicle (a hydrocele) that feels like a lump or swelling.

Depending on the cause you may also have difficulty peeing, or a white, yellow or green discharge from the tip of the penis. Symptoms can come on suddenly or gradually.

The epididymis is the tube behind the testicles. In epididymitis it becomes swollen and painful. The NHS says it is often caused by an infection and is usually treated with antibiotics.

NICE CKS describes epididymo-orchitis as including both epididymitis and orchitis (inflammation of the testicle), and lists it among several causes of scrotal pain and swelling that need to be told apart.

The NHS says epididymitis is usually caused by a sexually transmitted infection (STI), such as chlamydia or gonorrhoea, which is more likely in younger men under 35. In men over 35, the main cause is usually a urine infection.

A urinary tract infection (UTI) is more likely if you have an enlarged prostate gland, a urinary catheter or have recently had surgery to the groin, prostate gland or bladder. The NHS lists less common causes as mumps, tuberculosis, taking amiodarone (a medicine for heart rhythm disorder), a groin injury and Behçet's disease.

If tests show an STI, the NHS says it may be recommended that current or recent sexual partners (over the past 6 months) are also tested.

At a GP or sexual health clinic you will usually have some tests to find the cause. The NHS lists a groin examination, a swab of the urethra (the tube that carries pee out of the body) to test for infection, urine and blood tests, and a rectal examination to check for problems with the prostate.

NICE CKS says assessment of scrotal pain includes asking about the history of pain, swelling, sexual history, trauma and urinary symptoms, examination of the scrotum and groin, and arranging STI testing or UTI investigations if indicated. An urgent ultrasound scan of the scrotum is arranged when there is diagnostic uncertainty or persistent or unexplained symptoms.

The treatment is usually antibiotics, given as injections, tablets or a combination. The NHS says it is important to finish the whole course, even if you start to feel better.

To ease pain and swelling the NHS suggests painkillers such as paracetamol or ibuprofen (if you have a history of seizures or fits, NSAIDs such as ibuprofen should not be taken with some antibiotics used for epididymitis, so check with a pharmacist), holding a cold pack or bag of frozen peas wrapped in a tea towel on the groin, and wearing underwear that supports the scrotum.

If you have gonorrhoea or chlamydia, the NHS says not to have sex until you have finished the full course of treatment, or for 7 days after.

The NHS says you should start to feel better within a few days of starting antibiotics, but it may take up to 3 months to fully recover. If you still have symptoms after this, you might be referred for further tests.

The NHS suggests continuing the supportive measures above while recovering, and notes that sexual partners may need testing and treatment if an STI is the cause.

The NHS says to call 999 or go to A&E if you get sudden, unbearable pain in your testicles or tummy, because it could be a twisted testicle and needs to be treated in hospital as soon as possible. Do not drive yourself; ask someone to drive you or call 999.

NICE CKS says testicular torsion should be suspected in any person presenting with acute scrotal pain and swelling before other causes are considered, and that emergency hospital admission is arranged for suspected torsion or severe epididymo-orchitis with possible sepsis or abscess.

See a GP for a lump in the testicle, swollen testicles, a change in shape, one testicle becoming bigger than the other, or aching or discomfort that does not go away, because lumps can be a sign of testicular cancer, which is easier to treat if found early.

You can be assessed by a GP or at a sexual health clinic. The NHS says sexual health clinics can provide the same antibiotics you would get from your GP, and many offer a walk-in service. NICE CKS advises urgent referral to a sexual health clinic for suspected STI-related epididymo-orchitis.

Private GP and urology services are also available. The diagnostic steps and antibiotics are the same; the most important point is not to delay assessment of sudden testicular pain.