Testicular lumps and swellings are quite common and can affect males of any age. They can be caused by an injury or an underlying medical condition, which leads to a build-up of fluid, inflammation or an abnormal growth.

The swelling may cause no pain or it can be painful. If it is extremely painful, see a doctor urgently. Depending on the cause, a delay in treatment can cause the loss of your testicle as the tissue dies.

A swollen testicle or a lump in your testicle isn’t usually a sign of a serious condition. However, testicular pain should always be checked by your GP as it can be a symptom of an underlying condition. In most cases, testicular lumps and swellings can be successfully treated.

Causes of swollen testicles

Swollen, enlarged testicles can occur quickly or gradually over time. Common causes include:

Chlamydia — a common sexually transmitted infection (STI) caused by bacteria, which is usually passed on by having unprotected sex
Epididymo-orchitis — painful inflammation of the testicle and epididymis (the coil where sperm is stored), which can be caused by an STI, urinary tract infection (UTI) or, in boys, mumps
Haematocele — a collection of blood around your testicle, which is usually caused by an injury
Hydrocele — a build-up of fluid inside the scrotum (the loose pocket of skin surrounding your testicles), which can affect newborn male babies, boys and, most commonly, men over the age of 40
Inguinal hernia — a painful swelling in the groin area which is eight times more likely to affect men than women
Varicoceles — enlarged veins in the scrotum

Swollen, enlarged testicles can also be caused by spermatoceles or epididymal cysts. A spermatocele is an abnormal fluid-filled sac (cyst) in the epididymis, which contains sperm. Epididymal cysts are very similar but do not contain sperm. Both conditions cause testicular pain and a feeling of heaviness.

Rare causes of swollen testicles include:

Generalised oedema
Infections — this includes the bacterial STI syphilis and infection with roundworms
Rare inflammatory diseases — this includes Henoch-Schoenlein purpura and sarcoidosis
Sebaceous cysts
Skin cancer, specifically squamous cell carcinoma
Skin conditions — this includes allergic skin rashes and hidradenitis suppurativa

If you’re experiencing agonising testicle pain, nausea, vomiting and abdominal pain, and your scrotum is swollen and tender, call 999 immediately. You may have a testicular torsion. This is when the testicle, inside the scrotum, twists and cuts off its blood supply. This is a very serious condition which is most common in young males aged 10-20.

Most lumps in testicles are epididymal cysts, which are most likely to develop when you’re middle-aged.

A swelling or lump on a testicle is the most common symptom of testicular cancer. Testicular cancer is rare and is most likely to affect men in their early 30s. If you spot any change in the look or feel of your testicles, see your GP as soon as possible.

Getting a diagnosis for swollen testicles

See your GP if you:

Have a lump in your testicles, or an enlarged or sore testicle
Notice a change in the shape or feel of your testicles
Notice that one testicle has become bigger than the other

Your GP will examine your testicles and may shine a light onto your scrotum to check for excess fluid. If your GP suspects you have a hernia, they may ask you to cough. Your GP may also refer you for other investigations, such as blood tests, urine tests or an ultrasound scan.

After diagnosis, your GP may refer you to a consultant, such as a urologist, or to a genito-urinary medicine clinic.

Treatments for swollen testicles

At home

If the swelling or lump isn’t causing you any problems or testicular pain, treatment may not be needed. Warm baths may help reduce swollen testicles. In addition, avoiding strenuous activities, taking over-the-counter painkillers and wearing supportive underpants may relieve testicular pain.

Prescribed treatments

The treatment your GP or consultant recommends will depend on the cause of the lump or swelling affecting your testicle. If you’re diagnosed with a serious condition, such as testicular cancer, your doctor will arrange the necessary treatment. If an infection is causing your enlarged or sore testicle, your doctor may prescribe antibiotics.

Surgery

If you have troublesome varicoceles, your doctor may suggest surgery to reduce the swelling or remove the affected veins.

A hydrocele can be surgically drained while an inguinal hernia can be repaired with a straightforward surgical procedure.

Occasionally, surgery may be recommended to remove the lump on a testicle caused by an epididymal cyst.

Testicular torsion needs urgent surgery to restore blood flow to your affected testicle. Your testicular tissue will start to die if you don't receive treatment within a few hours.

Frequently asked questions

What to do if you have a swollen testicle?

This depends on the cause of your swollen testicle. If you are not in any pain and the swelling isn’t causing you any problems, you may not need treatment. You can manage your condition at home by:

Avoiding strenuous activities
Taking over-the-counter painkillers
Taking warm baths to reduce swelling
Wearing supportive underpants

However, if you have a lump in your testicles, or an enlarged or sore testicle, you should see your GP for a diagnosis and treatment.

You should also see your GP if you notice a change in the shape or feel of your testicles, or if one testicle has become bigger than the other.

Will a swollen testicle go away on its own?

This depends on the cause of your swollen testicle, which is usually injury or an underlying medical condition. If you’re concerned about your swollen testicle, see your GP. In most cases, there is effective treatment.

When should you go to the doctor for testicle pain?

You should always see your GP if you are experiencing testicular pain as it could be a sign of an underlying medical condition or an injury, which needs treatment.

Why is the left testicle more important?

The left testicle is not more important. However, the anatomy of the left testicle is slightly different from the right testicle. This makes it more vulnerable to certain conditions eg varicoceles and testicular torsion.

Should I worry about testicular pain?

Swollen testicles are common but do not always cause pain. If you have testicular pain, it is important to see your GP. You may have an underlying medical condition or injury that needs treatment. In most cases, your swelling and pain can be effectively treated.

Can testicular torsion fix itself?

No. Testicular torsion can’t fix itself and needs urgent medical treatment. It is caused by the testicle twisting in the scrotum and cutting off its blood supply. If it is not treated with surgery within a few hours, the testicular tissue starts to die.